It's Best If We Both Stay
by ipreferwestside
Summary: It feels like they might be crossing that line they've been toeing for years. That line between friends and something more. An early relationship AU.
1. Chapter 1

_You took the time to memorize me  
_ _My fears, my hopes, and dreams  
_ _I just like hangin' out with you, all the time  
_ _All those times that you didn't leave  
_ _It's been occurring to me I'd like to hang out with you, for my whole life  
_ Stay, Stay, Stay – Taylor Swift

* * *

 **IT'S BEST IF WE BOTH STAY  
CHAPTER ONE  
**

* * *

She's almost shaking as she stares at his door.

 _What the hell, Kate? You've been here a hundred times. Hell, you_ lived _here for a couple weeks. It's Castle. Your_ friend. _You're having a movie night. That's_ it.

Except it doesn't feel like a movie night with a friend. It feels like more. The slight hesitation in his invitation to join him, her admission a week ago that her wall is coming down; it feels like they might be crossing that line they've been toeing for years. That line between friends and something more.

And Kate is absolutely terrified.

She brings up his name on her phone, her finger hovering over the call button. She should turn around, go home, tell him she's not feeling well. She's tired; they caught a rough case, the ones with kids or teenagers always are, and he's seen how they can affect her. Especially when there's a delay. Forensics had been backed up, so the results on DNA found at the scene hadn't come back yet.

The door swings open before she can make her move, though, revealing Castle in jeans and a blue v-neck sweater that brings out his eyes, and _holy shit he looks hot._ She rarely sees him in sweaters anymore, since he opts instead for crisp button-downs. While she's glad the arrogant man-child from the first couple years is gone, sometimes she misses the casual look he would sport.

"Beckett!" Castle's giving her a wide grin, which morphs into a smirk when he glances down at her phone to see his own face smiling up at him. He cocks his eyebrow at her, amused. "Lemme guess. You were about to turn around and call me while you were leaving, saying that you're tired and should probably just rest."

Kate quickly locks the screen and shoves her phone back into the pocket of her jeans. "No," she argues, but there's no force behind it, and besides, he knows her tells. He'll know she's lying.

Castle steps to the side. "Liar," he teases. "Come on in. I just finished up the popcorn, I got some M&Ms and gummy bears. What would you like to drink? Wine, beer, I can make you something?"

Kate toes off her sneakers at the door, shoving her hands in her pockets as she follows him into the kitchen. "Um, water, I think. For now." She gives him a smile when he hands her a glass. "Thanks, Castle. How was graduation, Alexis's speech?"

"She was amazing, no surprise there." Castle puffs a little with pride. "She'd probably give an encore performance if you ask."

Kate takes a drink of her water with a smile. "Yeah, I'd love to hear it."

"Great. Shall we?" Castle takes a beer for himself and leads her into a room she hasn't been in before. He leads her through his office, and-

Of course he has a secret room that he's converted into a theatre. _Sure, why the hell not?_

It's small and cozy, a couch on one end of the room and a big-screen TV on the other. He has blankets piled on one of the ottomans in front of the couch, and there are pillows strewn all over the floor. She can't help but roll her eyes at the whole set-up; the nine-year-old on a sugar rush is still in him somewhere.

But who is she kidding? She loves that about him.

"Make yourself comfortable," says Castle, sweeping his arm towards the couch. "I'll be right back."

By the time he comes back, juggling the popcorn and candy, as well as two smaller bowls, Kate's leaning up against one of the arms of the couch, her toes tucked between the cushions and her head leaning against the cushions, eyes closed.

She opens her eyes when Castle sits across from her, a cushion between them, and gives him an embarrassed smile. "Sorry," she says quietly.

Castle hands her one of the smaller bowls and sets the snacks between them. "Are you sure you're up for this, Beckett? I know we're in the middle of that case, and it's been a long day…"

"No, no, I'm fine." Kate shifts, tucking her feet underneath her instead. "This is just a super comfortable couch."

Castle grabs a blanket and hands it to her. "Well, don't feel bad if you fall asleep," he says. "But you should know that I make a very nice pillow," he adds with a wink.

Kate rolls her eyes, tucking the blanket around her. "Just start the movie, Castle."

* * *

She starts to fade 20 minutes into the movie. She's warm under the blanket and the couch is a plush leather, much more comfortable than her own, which she'd collapsed on the previous night. She covers a yawn, then another, and finally when she barely catches the third Castle speaks up.

"Do you want to stop?" he asks quietly, pausing the movie.

Kate waves a hand as if to dismiss the thought. "No, no, it's fine. I'm fine." She ignores the pointed look he gives her, keeping her eyes glued on the screen in front of them even as he moves the food to the floor. _What the hell is he doing?_

Castle shifts so he's facing her, one leg curled on the couch. "Kate," he says quietly, tenderly, "you don't have to stay. We can do this another night."

She's shaking her head by the time he finishes his sentence. "Nope, we made a date."

As soon as the word comes out she freezes, eyes wide.

 _Shit._

They just stare at each other for a few moments, or hours, or days. She can see the desire in his eyes even from where she's sitting, the light from the TV reflecting in his dilated pupils so his eyes look wild, even a little dangerous. Like he wants to say "to hell with it" and just ravish her.

As if he knows what she's thinking, Castle's gaze flickers from her eyes to her mouth and back again.

"Is-" It comes out gruff and he has to clear his throat. "So, this is a date?" His voice is low and husky, laced with something that sounds suspiciously like desire.

The corner of Kate's mouth lifts in a half-smile. "Depends."

"On what?"

 _What are you doing, Kate?_

"On whether or not you want it to be."

Castle reaches his arm towards her along the back of the couch, their outstretched hands not quite touching. "I think I've made my intentions clear," he says slowly, his eyes on the space between their fingers. "You told me once about the wall you built inside, and you recently you said that it's coming down." He shifts his gaze to look in her eyes again. "I have every intention of bulldozing the rest of that wall until it feels like it never existed."

Kate nods, her eyes moving to their hands. She takes a deep breath and reaches out to brush her fingers against his, and he turns his hand over and curls their fingers together.

"I'm scared," she whispers, ignoring the rush of desire that runs through her blood at the contact.

Castle leans forward slightly so he can take more of her hand. "Of what?"

After a long minute, she finally meets his eyes again, her vision blurred with unshed tears. "Of me. Of us. This. I'll mess up, Castle. I'll do something stupid and fuck this up, and I'll lose you, and you're my partner, my best friend, and I don't know what I'd do without you."

"Hey." Castle squeezes her hand to interrupt. "I'm not going anywhere. I'll mess up too, but we'll figure it out. If we can survive a freezer and a serial killer and a bullet to the chest, we can survive a relationship."

Kate involuntarily curls her free hand to her chest, to the scar that caused so much pain for both of them, physical and emotional alike. Her voice shakes when she speaks again. "What if we don't?"

"What if we never try?"

She nods once, almost as if to seal her decision, and tugs slightly on his hand. She uses it as leverage to rise up on her knees and shuffle to his side of the couch.

"I'd like to try."

Letting go of his hand, she trails hers up his arm to the back of his neck, her other meeting it, and she kneels directly in front of him. Her fingers play with the fine hairs at his nape as she studies his face, the way his eyes flutter close at her touch. He obviously wants this, but the last few weeks, how withdrawn he's been...

Oh. _Oh._

"You know," she blurts out suddenly, the final piece of the puzzle clicking into place. "You know I heard you when I got shot. That's why you were upset, why you pulled back. You heard...but when?"

She's only inches from him, her eyes studying when he opens his. He holds her gaze until she finally gasps, the final piece clicking into place.

"That bombing case," she whispers. "Oh, God, Castle. That's why you left in the middle of the day. You heard the interrogation."

He just nods.

Kate shakes her head at herself. "I'm so sorry, Rick. I can't even tell you how sorry I am. You must have thought I didn't care. Shit. I really messed up." She moves her hands to his shoulders. "What can I do? How can I make this up to you?"

He's shaking his head before she finishes her question. "Nothing," he assures her. "You're here. That's enough for me right now. As long as I know you _do_ actually want this, that you're working towards it, I'm willing to wait until you're ready."

"You're amazing," Kate says quietly, a smile tugging at her lips. "I don't deserve you."

Castle finally brings his hands up to bracket her waist. "No, Kate," he whispers, shaking his head, his thumbs brushing against her ribs. " _I_ don't deserve _you_."

Kate pauses briefly before leaning forward to capture his lips with hers. It's soft initially, hesitant, but before long she slicks her tongue against his lips and he willingly opens for her. She kisses him slowly and deeply, acquainting herself with his taste, and Kate knows that she doesn't want anyone else.

She wants to spend the rest of her life with this man.

She pulls away before long, when his hands are dangerously close to the hem of her sweater and hers are itching to feel his skin. She searches his face when she pulls back, and his eyes are still closed, like he's trying to memorize the kiss they just shared.

Finally, Castle opens his eyes with a smile on his face. "That was..." He grasps for the right words.

"Amazing?" Kate supplies, reminding them both of the first kiss they'd shared, over a year before as an undercover diversion.

Castle quirks an eyebrow. "Epic also comes to mind."

"Epic, huh? Just wait until I get you in bed. You don't know what epic is yet," she teases.

Castle grins and starts to lean in when she suddenly yawns. "Well, I've never had _that_ reaction to a kiss."

"Shut up, Castle," Kate says lightly, nudging his shoulder. "Look, I want this. I really, _really_ want this."

"Me too." He sees the regret in her eyes. "But we're in the middle of a case."

Kate nods. "When we do this, like do _this_ this-" she waves her hand between them, "-I don't want to be rushing off to the precinct in the morning because forensics came back. I want to be able to enjoy myself. Enjoy you. Have a lazy morning, you know? Am I making sense?"

Castle reaches up and tucks an errant piece of hair behind her ear. "You're making perfect sense," he says quietly, brushing his thumb under her eye, at the edge of the dark circle underneath. "After the case? Try this date thing again?"

Kate gets off the couch and extends her hand, pulling him up to her when he takes it. She locks her arms around his waist and leans back to look up at him. "Absolutely."

She helps him clean up, taking the food back to the kitchen while he folds the blankets they'd used and puts the movie away. Kate gets lost in her thoughts as she washes the bowls and sets them out to dry, marveling at how comfortable she feels here. She knows where everything is; it's warm and inviting, the fireplace going almost nonstop during the fall and winter. Even now, with summer approaching, it's the perfect temperature inside. She loves being here. It's relaxing, and...home.

It feels like home.

She startles when Castle appears at her side to dry the bowls, and he smiles in apology. "I can finish up," he offers. "You go home, get some sleep. Better yet, why don't you stay here? You're always welcome."

Kate shakes her head. "If I stay here we won't be doing a lot of sleeping," she admits, her cheeks flushing. She rinses the pot he'd used for the popcorn and hands it to him. "After the case."

"After the case." He dries it and sets it aside to finish walking her to the door. "Thanks for helping clean up."

She slips her shoes back on, using his shoulder for leverage, trying to ignore the flash of desire at the feel of his muscles under her fingers. _Simmer down, Beckett._ She pats her pockets: keys and phone, check. "Thank you for understanding," she says quietly, looking up at him through her lashes.

Castle takes her hands and leans down to give her a soft kiss. It's just a meeting of the lips, nothing more, and he pulls away before she can surge forward for more. "Always, Kate. See you tomorrow."

"Good night, Castle."

* * *

 _A/N: Some ideas are born out of Twitter conversations. Some are prompted. This is a combination of both. This fic is for Ally, Callie, Cathey, and Lou, who heavily encouraged me to write this. So, ladies, this is for you._

 _So many thanks to Callie (whatifellinlovewith) for betaing this and putting up with my insecurities, and also for the awesome cover art that I am absolutely in love with._


	2. Chapter 2

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER TWO  
**

* * *

The next morning Kate is staring at her coffee maker, willing it to brew faster, when she gets the call. Despite Castle's encouragement, she'd barely slept the night before. She couldn't stop thinking about their kiss, the way her body responded, how his hands and tongue felt against hers...

She snaps out of her thoughts with the shrill ring of the phone.

She answers immediately, reflexes fast when she sees the number, despite her tired state. "Beckett," she answers sharply. She listens to the tech as he explains the results, and by the time he's finished she's slid into a chair, eyes unfocused ahead of her. "Are you sure?" Somehow she keeps her voice even. "Okay, thank you. Thanks for calling me."

 _No. God, no._

Ten months of nothing. And now…

Her fingers dial Castle before she knows they've even moved, but by the time she goes to end the call he's answering.

"Beckett?" A pause, then he clears the sleep from his throat and speaks louder. "Beckett? Kate, are you there?"

Kate brings up the phone to her ear slowly, like she's not in control of her motions. "CSU just called me," she says. "Preliminary DNA came back." She's trying desperately to keep her voice steady, but she wouldn't be surprised if Castle hears the slight tremble.

"What did they say? And do they usually call you directly at an ungodly hour?"

Kate shakes her head briefly before realizing he can't see her. "No. Usually they'd set the results on my desk and send me a text saying they're in."

"So what's different?" Castle pauses, but when she doesn't answer right away he continues. "Kate, talk to me. What did they say?"

"The—" She has to stop and take a deep breath, wills herself not to break down. "The DNA matched someone that was in the system. It was from another case, an unsolved shooting." She swallows around the lump in her throat. "My shooting, Castle. The guy who Orlando Costas fought, the suspect in this case...was the same guy that shot me."

"I'll be there in 15 minutes."

"Castle—"

"Not a question, Kate."

She manages to take a quick shower and get dressed before he gets there, but as soon as she opens the door he's pulling her into a hug, ignoring her still-wet hair. She closes her eyes and sinks into his embrace for a few moments before taking a deep breath and pulling back. "Thanks," she says, giving him a tired smile.

Castle returns her smile and lightly cups her cheek, brushes her cheekbone with his thumb. "You're welcome. How are you doing?"

She shrugs as he follows her into the kitchen. "I'm not sure. I don't think it's really sunk in yet. Coffee?"

"Please."

She goes through the motions of pouring the coffee and a little cream and sugar to both mugs, adding some vanilla syrup to her own. They sip in silence, finishing at the same time, and Castle sets both of their mugs in the sink before turning back to her.

Castle studies her for a few moments, eyebrows furrowed. "Did you sleep well last night?" he finally asks.

Kate pinches the bridge of her nose, trying to stave off the headache already forming, and shakes her head. "Not really," she confesses in a quiet voice. She reaches out and squeezes his hand. "I should finish getting ready."

When Kate comes back out she's pulling her hair back, and she slips on her shoes and coat quickly; badge goes in her pocket, gun in her holster, and her cop persona is in the forefront once again.

She pauses at the door and takes a deep breath before turning back to Castle, a smile sneaking onto her features when she sees him staring at her, awe written all over his features. "You coming?"

* * *

The precinct is quiet. It's before 6:30 when they exit the elevator together, and Beckett goes straight to the murder board after dropping her bag in her chair. She perches at the edge of her desk, staring, trying to find the clue to link this case to her own, besides the DNA.

Castle joins her after a few minutes, having taken a detour to the espresso machine, and gives her a small smile when she lets her fingers brush against his as she takes the mug. "The cases might not be related," he offers, but it's weak even for him.

"Costas broke into Montgomery's house, Castle," Beckett points out. "How can they not be? It's the same shooter. They're connected. I know they are."

"Kate—"

"Ten months, Castle. Ten months of nothing, not even a glimmer, and all of a sudden, this? It's too much of a coincidence." She pauses to take a sip of the latte he made her, not so much for the caffeine but to give herself a moment. "Since my shooting I've been waiting for something to happen, for the dragon to rear its ugly head again. For the other shoe to drop. Everyone that was involved is dead, except for me. What if this is it? What if this is the other shoe?"

Castle reaches over and takes her free hand in his, lacing their fingers together. "If it is, I'll be with you. Every step of the way. And I won't let anything happen to you."

Kate smiles, and after a quick glance around the precinct to make sure they're still alone, she brushes a quick kiss against his mouth. "Thanks, Castle," she says quietly. She looks down at their joined hands. "Just...can you promise me something?"

"Anything."

"Don't let me get lost in this again? We're in a good place, and I...I don't want to get drawn back into the rabbit hole again. But I don't know if I'll be able to stop myself."

Castle wraps his arm around her shoulders and pulls her close. "Of course."

* * *

A few hours later, Castle isn't sure he can keep his promise. Kate had lost it while interrogating the victim's girlfriend about the money they'd been wired, which had admittedly resulted in a fairly solid lead. They have a face, but when Kate forbids Ryan and Esposito from running it through facial recognition software, making it almost impossible to identify him, Castle knows that she's on the edge. Especially when she snaps at him after he simply says her name.

Which is why he finds himself at her door that night, both physically and emotionally exhausted, but needing to talk her down. She shouldn't be investigating. It's only a matter of time before they come after her again.

The door opens moments after he knocks, and he doesn't miss the gun at Kate's side or how tired she looks. She's been going hard all day long, and the lack of sleep and emotion from the day seems to be finally catching up to her.

"Hey," she says, stepping aside to let him in. "Espo called a few minutes ago. He said the shooter had a keychain, with a logo, and he tracked it down to a parking garage out in the Bronx. He's running it down now, seeing if they keep copies of driver's licenses on file."

"Kate—"

"I know, he'll be using a fake ID, It's still a needle in a haystack, but at least we have a haystack. So tomorrow—"

 _"Kate."_

She finally turns back to him, eyebrows raised, and she reaches out and takes his hand. "What's wrong?"

Rick sighs and takes his other hand out if his pocket, holding a flash drive. "You need to stop. The investigation. You need to let it go. Step away, let the boys handle it, something. But you can't be involved anymore."

Kate just stares. "You don't have to worry about me, Castle. I'm fine. I'm in control."

"No, you're not." He walks past her to her computer and wakes it up, plugs in the flash drive. "You're not in control. Look, I need to show you something." He brings up the contents of the drive: the digital murder board he created to work her shooting.

Kate takes a step forward, her eyes glued to the screen. "What is that?" Her face stares back at her, and when Castle clicks on it and others appear, she gasps and stumbles back.

It's her case.

Her case, and her mom's case, and it's an almost exact digital replica of the board decorating the window just a few feet away.

"Castle...what the hell is this? What have you done?"

Castle drops his head briefly, then starts to explain. "Last year, when you were in the hospital, I got a call from an old friend of Montgomery's. He'd received a package, a file that contained evidence damaging to the person behind your mother's murder. Before he went to that hanger, Montgomery had sent the file as insurance, to keep them from going after you. But Smith didn't get the file until after you'd been shot."

Kate leans forward. "Smith?"

Castle takes a deep breath before continuing. "Montgomery's friend. He told me the deal was that they wouldn't come after you as long as you weren't investigating. So...he enlisted my help."

"You're a part of this?" Her voice breaks, barely suppressing the tears in her eyes.

Castle reaches for her hand, wincing when she pulls it back, away from him. "I was just trying to keep you safe."

"By lying to me about this? God, Castle, you _know_ what this case means to me."

"I was trying to protect—"

"I don't need protection, Rick!" She's yelling now, angry tears rolling down her cheeks. "I needed a lead on the guy who shot me, the guy who _had my mother killed_ and you sat on it for almost a year. A year! How did you know you could trust him? What if he's behind it all? And how the hell could you do this?"

Castle finally breaks. "Because I love you!" he yells right back, and the way she just stares is devastating, but he keeps going. "I've loved you from the start, Kate. Four years, I've been bringing you coffee just to put a smile on your face. I couldn't tell you, couldn't see you go down that path again—"

"What path, exactly? The path where I killed the man who stabbed my mother? Or the one where I'm still alive?" Her fists are clenching and unclenching. "You should have told me, Rick. You should have let me decide for myself. And now they're cleaning house, so they'll probably come after me anyway."

"No." He's in front of her in three long strides, too fast for her to back away. He takes her hands and squeezes them, willing her to look up at him. "I won't let anything happen to you. But you need to walk away."

Kate tears her hands from his grip. "I can't walk away from this. I won't."

"They've turned this into a war that I don't think we can win."

"Then _you_ can walk away."

They stare at each other for a full minute, both struck mute from the words that just came out of her mouth. Finally, Castle nods in resignation and turns away. "I thought you wanted this. Us," he says quietly, waving his hand between them. He gives her one last long, sad look before turning to the door. "I guess not."

* * *

It's late morning when Castle's phone starts to ring. After a few hours of tossing and turning, he'd tried to write, but his fight with Beckett consumed every thought, so he'd given up after just a few minutes.

They'd been in such a good place after their failed movie night; both had admitted they wanted something more than friendship, and she'd proven that his memory of her kissing ability was very accurate. And she'd even kissed him in the precinct. Granted, it was at 6:30 in the morning after she'd made sure nobody was around, but a precinct kiss was a precinct kiss.

But now…

He'd ruined everything.

He ignores his phone as long as he can, but after a half dozen times of it stopping and starting his nerves are getting the best of him. The previous ignored calls had been from the precinct itself, no doubt one of the guys trying to get a hold of him for some reason or another. But he finally answers when he sees Ryan's name on the screen.

"What is it?" he asks sharply, half expecting Beckett to be using the phone.

"Castle, thank God." No, it's Ryan, but he sounds panicked. "Beckett and Espo went after the sniper, with no backup. I tried to stop them, but they wouldn't listen."

Castle barely suppresses the urge to run towards the door at the mention of Beckett in danger. "Look, Ryan, I'm done. I can't go through this anymore, watching…I just can't."

"This guy is dangerous, Castle. I'm on my way with SWAT but they have at least a half-hour head start. He's at the Roslyn Hotel. It's not that far from you, if you get a hold of Beckett first maybe you can talk her down." Ryan pauses and takes a breath. "I don't know what happened between you two, and frankly it's none of my business, but Castle, they're running headfirst into a suicide mission. He almost killed her before. I'm not so sure he won't succeed this time."

Castle runs his fingers through his hair in frustration before making up his mind. "You said the Roslyn?"

* * *

He arrives mere moments before SWAT, but starts to bound up the stairs before they've even unloaded from the van. He barely hears Ryan shouting after him to wait for one of them, or at least take a gun, but he doesn't care.

He's meets Esposito about halfway up, barely stops to make sure he's okay. _He's standing, he's fine._ Espo yells after him that Beckett went to the roof.

 _Oh God._

"Beckett! Kate!" Castle yells her name louder than he ever has before when he bursts through the door. From what he can tell, the roof is empty, but after a few moments he hears her call his name, loud and clear and - _oh shit_ \- coming from the side of the building.

Castle runs towards the sound and sees her hands, fingers balancing precariously on the edge of a ledge, and he leans his head over to see her hanging on, just barely. Her eyes are wild and panicked, but relief washes over her features when she sees him.

"Castle—"

"SWAT's right behind me. Just hang on. Hang on, Beckett!" He reaches for her, but she's just out of reach, only by a few inches.

"Castle, I can't, I—" Kate's eyes widen when her right hand slips, and she's holding on just by her left, and it's slipping, until it's just her fingertips…

"NO!" Castle lunges forward and grabs her wrist just as the last finger slips away and she starts to fall. He manages to grab the ledge with his other hand to keep himself from sliding over the edge with her, and he stares into her eyes, holds them with his own. "Hang on, Kate. Just don't let go of me. Look at me. Keep looking at me."

She manages to keep her eyes on him. "Castle—"

Just moments later Castle feels hands at his shirt and belt, and Ryan is helping him pull Kate up, with help from a couple SWAT members. Kate grabs onto Castle's arm as soon as she can swing her right arm up, and as soon as Castle is able to, both of his arms are around her back, and he's pulling her over the ledge, back onto solid ground.

Kate collapses on top of him, fists gripping his shirt, face buried in his chest. "I'm so sorry, Castle," she sobs, her whole body shaking even as he holds her. "I should have listened to you—"

"Hey." Castle dusts a kiss over the top of her head before cupping her cheeks and tilting her head so she can look up at him. "No, Kate. I should have been here. I'm sorry." He tucks her head back into his chest when her tears start to fall again. "You're okay, Kate. You're okay."

* * *

 _Again, thanks to Callie for the beta and the cover art! 3_


	3. Chapter 3

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER 3  
**

* * *

"Lying to your superior officer, disobeying a direct order, insubordination? I should have _both_ of your jobs!"

Every word Gates is saying to Beckett and Esposito echoes through the bullpen, despite her closed door. Castle sits dutifully in his chair next to Beckett's desk, his back to Gates's office, and for that he's grateful. Although he's sure Kate's face is neutral; she's probably taking the verbal dressing down like a champ.

Finally, after a few more minutes that end with quieter words Castle can't quite make out, he hears the door open forcefully, and Beckett touches his shoulder when she walks around him.

"You okay?" Castle asks, noticing the look on her face. She definitely doesn't look like he expected. He'd figured that she'd be mad, maybe have that rebellious fire in her eyes that he's seen many times before. But not this. She almost looks…happy.

Kate grabs a box from the desk behind her and starts clearing off her own. "I'm fine. Good." She pauses to give Castle a smile. "Perfect. I resigned."

"You…what?"

Kate chuckles as she carefully sets her elephants into the box. "I resigned. I'm done." She finishes packing and starts walking out without saying another word, and Castle follows, as usual.

She leads him to the lobby and out to the street, where she hands him her box so she can hail a cab.

Castle still hasn't said a word, but when she gives the driver her address, he finally opens his mouth. "Kate, what's going on?"

Kate doesn't answer him right away, looking out the window instead. Finally, when Castle touches her forearm, she turns her head back to him with a smile and a gleam in her eye. "We're going to my place," she says, covering his hand with hers. "And we're going to continue what we began the other night."

Castle just stares. "Kate…what…I mean…"

Kate giggles at his stammer. "I'm done being a cop, Rick. It's not worth it anymore. For years I just wanted the justice for others that I couldn't get for my mom, but now?"

She falls silent when the cab pulls in front of her building, paying and meeting Castle on the sidewalk. She leans into him for a quick kiss before leading him inside. "It's not worth it anymore. I don't want to live my life just waiting for the next body to drop. I can't watch people lose their lives too soon while I barely live mine."

By this time, they're at her door, and Kate unlocks it, leaving it open for Castle to follow her. He hesitates at the threshold; the last time he was here, he'd walked out, not expecting to be back.

It feels like a lifetime ago.

Kate drops her keys on the kitchen counter, turning back when she hears Castle stop. She walks back to him, toeing off her shoes as she does, and reaches up to touch his cheek. "Hey. You okay?" she asks quietly.

Castle nods slightly, looking down at her afterwards. "Yeah, I think so. I just…well, to be honest, after last night I didn't think I'd be here again for a long time. If ever." He finally steps inside and sets the box next to her keys, turning back to Kate while she locks the door. He crowds against her back, his hands on her waist, and he doesn't miss the shiver that runs through her body at the contact. "I'm glad I'm here now, though, even if it took what happened today to do it."

Kate turns in his arms and wraps hers around his neck, staring up in his eyes. "Thanks for coming to get me," she whispers. "You saved my life. Again. Thank you."

Castle leans down to capture her lips with his, drawing a moan from her as his tongue seeks hers. He echoes her moan when she hooks a leg around his thigh, rocking her hips against his. "Kate," he gasps when he has to pull away, desperate for air. "Oh, God, Kate."

Kate's lips trail past his jaw to his neck while her hands work at unbuttoning his shirt. She sinks her teeth into his shoulder when he pushes her against the door, and he answers with a jerk of his hips. She pushes his shirt from his shoulders and tugs off his undershirt, and pauses her assault on his belt only when he nudges her jacket and shirt off.

Their clothes fall to the floor in a tangled heap, and before Castle can drop to his knees in front of her, she takes his hand and leads him to her bedroom.

* * *

Kate has no idea how long she sleeps; her first thought when she regains consciousness is that something is tickling her back. She groans and tries to swipe at whatever it is – she figures it's probably her sheets – but when her hand connects with something solid that grunts, she wakes immediately.

She tries to roll over, but before she can, she sees Castle's face pop into her peripheral vision. "What are you doing?" she asks, her voice low, gruff with sleep.

Castle grins at the sight before him, at her sprawled against her sheets. He leans in to peck a kiss on her lips, chuckling when she barely responds. "I'm kissing your bruises to make them better," he explains with a smile.

Kate just grunts and settles further into her mattress, closing her eyes as Castle brushes his lips against her ribs. Before being thrown off the roof she'd had a bit of a beating, the man who shot her much stronger and more skilled than she is. It doesn't hurt yet (although Castle _has_ been doing a great job of distracting her), but she knows that it's only a matter of time.

Castle leans back on his elbow, staring at the darkening black and blue pattern across her back. He brushes a final kiss to the nape of her neck and settles in beside her, snuggling against her side. "I'm sorry," he whispers into her shoulder.

Kate manages to turn her head so they're nose-to-nose, so close their eyes almost cross when they look at each other. "Why?" she returns, bringing one hand to the side of his face.

Castle tilts his head so he can place a kiss against her palm, and brings his hand up to cover hers. "For walking out. I should have stayed. If I had, you wouldn't have these." He motions to her torso, to the bruises. "You wouldn't have run after him, wouldn't have been thrown off that damn roof."

"No, Rick." Kate leans forwards and kisses him, hard and bruising, nipping at his bottom lip before pulling away. "I still would have gone after him, and I might be dead. But I'm not, and we're here now, and I haven't felt this good in a long time. Maybe ever," she confesses, a grin creeping over her cheeks at the way Castle preens. "Don't get cocky."

"I can't help it," Castle teases, moving even closer, swallowing her moan when his hand wanders south. "You like it when I'm cock—"

Kate shuts him up with a kiss.

* * *

Later, Castle wakes to an empty bed and the sound of running water, and he sits up, looks around for Kate. He cranes his neck and spots her in the bathroom, her robe on and loosely tied as she pulls her hair back in a messy bun. She can't see him from where she is, so he takes the opportunity to watch, entranced by the glimpse of domesticity he's now privy to.

After a few minutes, Kate moves to the tub and turns off the water, then turns back towards the bedroom. She freezes when he sees Castle watching her, a shy smile on her lips as she tugs at the sash on her robe. "I was about to wake you," she says quietly. "Thought a bath might help with the soreness. Care to join me?"

Castle almost falls as he scrambles out of bed, his feet tangling in the sheets, and he grins at the amused look on Beckett's face. "I'd love to," he says, coming to a stop in front of her.

He gets in first, the water warm against his skin, Kate even warmer as she sinks in with her back to him. He hisses when she wiggles her hips, scooting back so she's nestled between his legs. "Kate—" he says quietly, his voice a low groan.

Kate turns her head so she can brush a kiss to his jaw. "Can we just sit for awhile?"

Castle lightly tugs her arms, bringing her with him as he leans back, his arms wrapping around her front so she's secure to him. "We can sit here as long as you want," he murmurs in her ear.

They stay like that until the water cools, and even longer when she sneaks her hand between them and they warm it back up.

* * *

The next morning, Kate wakes slowly, consciousness bringing with it the smell of flowers and coffee. She lifts her head in confusion; the bed beside her is empty, but the coffee on her nightstand is still warm. She sips at the to-go cup as she plucks the card out of the bouquet of flowers that sits next to her lamp.

 _Kate,_

 _Good morning, my sweet. (Too sappy? You'll get used to it. I am a writer, after all.) Didn't want to wake you; I have to take Mother and Alexis to the airport, but I'll be back soon with breakfast. Then we can properly celebrate your first day of freedom._

 _Always,_

 _Rick_

She can't help but smile. It is sappy, both the pet name and the bouquet he'd obviously brought with the coffee, but she hasn't had a guy bring her flowers since…well, since Castle himself had the previous year, after Raglan had been killed. She runs her fingers over the pedals before climbing out of bed. If he's going to the airport and back, she may as well take advantage and shower.

She's surprised when she hears a knock on the door barely two hours later, as she's just starting the coffee pot. Castle shouldn't be back yet; it takes at least an hour each way, and even if he had just dropped the ladies off and turned right back around, he should still be on his way.

Better safe than sorry (Cole Maddox is still out there, after all), she grabs her gun from her bureau, and holds it slightly behind her when she checks through the peephole. _Oh._ "Hey, Ryan," she greets, letting him in.

Ryan gives her a small, sad smile when he walks into her kitchen. "Hey, Beckett. How you holding up?"

Kate shrugs while she pours coffee for them both. "Um, I'm good. What's up?"

Ryan looks hesitant. "I need to talk to you about the case."

"Ryan…" she begins, but another quick knock on her door interrupts moments before it opens.

"I hope you're hungry, because I brought food so we can go all—oh. Ryan." Castle freezes just inside the door, looking between Ryan and Kate. "Hey. What's—what's up? I didn't know you were here, I would have brought you something too." He lamely holds the pastry bag that holds exactly one bear claw.

Ryan shifts his gaze between Castle and Beckett. "I…just stopped by. What are you doing here?"

"Well, Mother and Alexis just left for Europe, and Beckett and I are …" Castle trails off when he sees Kate move out of Ryan's line of sight and shake her head. "Well, we're hanging out today. I'm here to distract her from her unemployed status. What are you doing here?"

"I just came over to apologize. For what I did, for involving Gates. I know that's why you resigned," he adds, turning back to Kate.

"No, Ryan," Kate interrupts. "It's fine. You don't have to apologize, I get it. I should have listened to you. If I had, maybe we would actually have Maddox in custody. I didn't resign because of that. I resigned because I couldn't let the case control my life anymore. It's time to move on."

"So we're good?"

Kate nods. "Of course." She finally asks the question that's bothering her when Ryan heads towards the door. "Hey, did you figure out what picture they took from Montgomery's wedding album?" She ignores Castle's sharp intake of breath behind her.

Ryan shakes his head. "No, Evelyn's looking for the negatives, but apparently she recently had water damage in her storage and she's still going through everything to see if they were spared. We may never know." He shrugs before opening the door. "See you guys later."

"Bye." Kate locks the door behind Ryan and turns back to Castle. "This case will never go away, will it?"

Castle holds his hand out to her, pulling her into his arms when she takes it. "Probably not," he answers. "But I'll always be here, by your side. You'll never work it alone."

Kate smiles and sinks into his embrace. "Thanks, Castle." She pulls back when she spots the pastry bag on the counter. "What'd you bring me?"

Castle chuckles. "A bear claw. It should tide you over until lunch, because I fully intend to distract you for the rest of the morning."

"I want to take you out."

"Hmm?" Kate lifts her head from its spot on Castle's chest to look at him. "Out?"

"Like a date." Castle brushes her hair from her forehead so he can press his lips to her hairline. "I want to take you out. Dinner, drinks, the whole nine yards."

"Mmm," Kate hums appreciatively as she leans up to kiss him. "So not just a burger and shake at Remy's?" she teases, sliding to straddle his waist.

Castle's hands migrate to her hips and he grins. "Well, Remy's is great. But I want to wine and dine you."

"You don't have to wine and dine me, Castle." Kate kisses him again, deeply, and smiles against his lips. "But I won't say no to a night out."

* * *

 _A/N: Thank you for reading! Thanks to Callie for the beta!_


	4. Chapter 4

**IT'S BEST IF WE BOTH STAY**

 **CHAPTER FOUR**

* * *

She's just putting the finishing touches on her makeup that evening when she hears the knock. She knows nothing about what Castle has planned; he only said that he'd be picking her up at 6, and they'd be going someplace nice, "no ifs, ands, or buts about it." So she's wearing a deep blue cocktail dress that Lanie had insisted she get because it made her legs look "really damn sexy." She's noticed that Castle likes to play with the ends of her hair when they're lying in bed, so it's down in soft curls.

She opens the door with a smile, and feels her face flush when Castle's pupils darken as he takes in her outfit. "Hey Castle," she greets him, and eyes the bouquet at his side. "Are you just going to stand there or do you want to come in?"

Castle starts at her words. "Oh. Um, yeah. Wow, Kate, you look...you look great."

She grins and gives a little twirl. "You've seen me in nicer dresses than this," she points out, teasing him.

"Well yeah, but it's always been undercover, or that time you went out with Mr. July." He steps through the door, leaning down to kiss her cheek. "Never for me. These are for you," he adds, holding out the flowers.

"Thank you." Kate leads him to the kitchen, where she finds a vase and arranges them. She turns back to him and reaches out to thumb the collar of his deep green shirt. "Do we need to go right away?"

"No, we have a few minutes. Why?"

"Because I really want to do this." She cups the back of his neck and pulls him to her. His mouth opens on a groan when her tongue swipes against his lips, and she presses her body flush against his, rising up on her bare toes so they're almost the same height. She lets him push her against the counter, but when his hand starts to creep under her skirt she pulls away.

"Do we have a reservation to get to?" she gasps as his lips trail down her neck.

Castle grunts and lifts his head, and he looks at her with hooded eyes. His fingers play with the strap of her dress. "Uh…yeah." He blinks several times, as if to blink away his arousal, and follows her to the door. "Do we have to?"

"Yes, Castle. I'm hungry."

* * *

The restaurant he takes her to is just a mile and a half away, but they take his car anyway. She prods him the whole way about where they're going and what they're doing, but he refuses to tell her anything, only says that the restaurant is one of his favorites and that he's wanted to bring her here for years.

"Since I met you, Kate," he says quietly, lacing their fingers together. "This is going to be really, really cheesy. But this place is special to me. I never even took Meredith or Gina here. It just…it didn't feel right. You know?"

"Yeah, I think so. And you're right, it's really cheesy." Kate smudges a kiss along his jaw with a smile. "But I love it. And if it means a lot to you, it means a lot to me."

Castle turns his head and captures her lips with his, reaching up to tenderly cup her jaw, exploring briefly before the car comes to a stop. As soon as they step hand-in-hand into the restaurant, the owner greets them with a smile and leads them to the private room that Castle had reserved.

Castle keeps an eye on Kate's reaction when they step into the basement, a large wine cellar that's stacked floor-to-ceiling with bottles. She looks absolutely floored, her jaw open in wonder, and when she sees the small candlelit table in the middle she looks at him with a grin.

"Really, Castle? You reserved a _wine cellar?_ " She's teasing, and she lists into his side, her cheek meeting his shoulder briefly, smiling when he takes advantage and presses his lips to the top of her head.

Castle grins against her hair and leads her to the table, where he pulls out a chair for her before taking his place at her side. "It's not just _any_ wine cellar." He pauses to allow the waiter to pour him some wine, and he samples it, nodding appreciatively. "This cellar allegedly inspired Edgar Allan Poe to write _The Cask of Amontillado._ So, you can see why I like this place."

Kate smiles at his excitement. "Yeah, I can." She lets him brush his lips against her knuckles before leaning in for a kiss. "This is amazing, Rick," she whispers against his mouth. "I love it."

* * *

They laugh their way through dinner, Castle sharing about some of the more ridiculous people he's met during research, Kate describing awkward arrests from her patrol days. He's heard a few of them before, but Castle doesn't mind; he could watch her like this forever, talking animatedly with her hands, a smile never leaving her lips.

He pays, tutting when Kate offers to leave the tip, and as they slide into his town car he can't help but smile at her little huff of frustration.

"You could have let me leave the tip, Castle," she insists, glaring at him with as much fire as she can muster. It doesn't have much weight behind it, though, and he easily tugs her into his side.

Castle slides his arm around her shoulders, relishing the way she leans into him. He likes this Kate. She's by no means a damsel in distress; as much as he wants to protect her, she's strong and independent and can definitely take care of herself. But now she's showing him this other side of her, the soft romantic, and he really, really likes it.

"It's called a date for a reason, Kate. I want to woo you tonight. Let me woo you." He lifts her chin with his finger and leans down to brush a kiss against her lips.

She responds almost immediately, bringing a hand up to curl around his neck, the other laced with his. Their mouths work against each other as the car moves through the streets, but when his fingers inch towards her hair she pulls away.

"Do we have other plans?" she gasps against his mouth, nudging her nose against his cheek.

Castle lets out a low groan. "Kinda, yeah."

"Can we reschedule?"

"Not really."

Kate scoots to put a few inches of space between them, even though the glance at his lap hints at her desire. "Then we should probably stop before you mess up my hair." Her face is serious, but the glint in her eye and smile in her voice betrays her.

"Challenge accepted." Castle lunges for her, but before he can continue his assault on her mouth the car rolls to a stop.

Kate pushes on his shoulder when the driver opens the door behind him. "Later, Castle." She eyes the line that snakes along the sidewalk when she follows him out of the car, and tucks her hand through his arm. She starts to move towards the line, but Castle pulls her towards the door.

He grins down at her. "We have a reservation," he says matter-of-factly, as if he's offended that she even questions it. "Besides—"

"You know a guy," Kate finishes with a smile.

The hostess of the little jazz club leads them to a booth in the back, where Castle slides in next to the wall, tugging on Kate's hand lightly so she scoots in next to him. Normally he'd let her in first, but he's seen how she likes to sit at the end of a booth, so she can get out easily if needed. He knows it's her cop training, and he thinks it's sexy as hell.

The martinis he orders for them arrive quickly, and they sip in relative silence, both taking in the environment and enjoying each other. The way Kate leans into his side and tucks her hand in his suddenly makes him wish he hadn't made these plans. He just wants to take her home.

He's just about to suggest they leave when the band comes onstage and starts playing, and he feels her relax into him even more. He smiles and presses his lips to her hairline, slipping his arm around her shoulders.

Yeah, he's good here.

* * *

They forego the car on the way back, partly because they're just a few blocks from Kate's apartment and partly because she wants to walk off the drinks she had at the club.

It's a cool night, and Kate shivers as she leans into Castle's side, goosebumps erupting on her arms. She has a sweater, but it's thin; she didn't think to bring anything thicker.

"You okay?" Castle asks quietly, his hand coming up to cover the one looped through his arm.

Kate shrugs. "Just a little cold, that's all."

He immediately pulls away from her and shrugs off his jacket, draping it over her shoulders. "I can get the car if you want."

"No, don't." She reaches for his hand again and lets him tug her back into his side. She stumbles a little, a little unsteady on her feet, and giggles when he holds her up with his arm around her waist. "Thanks, babe."

Castle quirks his eyebrow at the endearment. "Babe?" He squeezes her waist, and takes advantage of a stoplight to look down at her. "You called me babe."

Kate pulls his head down for a kiss and deepens it for a moment before pulling away. "Yeah, I did. It kind of slipped out. What do you think?"

He stares for a moment, taking in the woman in his arms, the bite of her lip accompanied by the gaze through her lashes. Finally, he tugs at the lapel of the coat and brushes a soft kiss to her mouth. "I think I want to take you home."

* * *

"Kate, over here!"

Kate hears her name over the din of the Remy's lunch crowd a few days later, and quickly spots Lanie. They share a quick hug; they haven't seen each other in the week since Kate resigned, and this lunch date is very overdue.

"Hey, Lanie," she greets her friend, sitting across from her. "Sorry I'm late. I was just—"

"Shacking up with Castle?"

Kate freezes. "Um…"

"Can I get you ladies something to drink?"

Lanie looks up at the waiter with a smile. "Just water for me, please. Kate, you probably need coffee, right?"

Kate just glares at Lanie for a moment. "Coffee would be great, thank you," she tells their waiter. As soon as the young man is gone she turns back to Lanie. "What are you talking about?"

Lanie just leans back and smirks. "Come on, Kate. Ryan said that Castle just waltzed into your place like he owned it, with coffee and a pastry. He didn't believe for a _second_ that you two were, and I quote, 'just hanging out.' And this—" She waves her hand in front of Kate's face. "You're glowing, Kate. I haven't seen you this happy in a long time. So." She leans forward and settles her elbows on the table. "How long?"

Kate shakes her head slightly, not quite sure what's happening. She and Castle had considered keeping their relationship quiet for a while, but decided to tell their friends and families. And judging by Martha and Alexis's excitement when they'd been told, it had been a good choice.

"Castle and I have decided to pursue a relationship, yes," Kate says slowly, wincing at the loud yelp that escapes Lanie. "Can you keep it down?"

Lanie reaches across the table and grabs both of Kate's hands. "Oh my God, I knew it. I _knew_ it! So, what's he like?"

Kate shushes Lanie, but she's smiling nonetheless. "He's great."

"That's it? Details, girl. I need details."

"I'm not—"

They're interrupted by the waiter again, who brings Kate's coffee and takes their orders, and when he leaves Lanie leans closer.

"So?"

Kate smiles as she thinks about just an hour before. He'd taken her in her bathroom, hot and quick against the sink, and though he'd made her late to lunch, it had been _amazing._

But Lanie doesn't need to know _everything._

"He's wonderful," Kate says, a flush creeping over her cheeks. "He's kind, and considerate, and Jesus Christ, he knows what he's doing."

Lanie just grins. "Girl, you have it bad for him. Have you set a date yet?"

"Oh my God, Lanie, it's been a _week!"_

"Mm-hmm. So you're in the 'spend every minute together and do it all the time' stage." Lanie leans back and gives her a nod. "Girl, I've seen how that man looks at you, and you look at him the same damn way. You two are crazy about each other."

Kate smiles around her coffee mug. Lanie's right; she's crazy about Castle, and she has been for a long time. "Maybe I am," she concedes, "but this relationship thing is still new. We've only technically been on one date, like a real, 'we both know it's a date' date."

"What did you do?"

Kate dives into a recap of their night out, from the private dinner at the restaurant to the corner booth at the jazz club. Lanie audibly sighs when Kate describes that Castle had had the band dedicate a song to her, and although Kate leaves out some of it – Lanie doesn't need to know just how much making out happened in the car – she's noticeably impressed at the end.

"You do realize," Lanie says once she's done, "that it's only a matter of time before there's a ring on your finger."

"That may be the case, but it's new right now. I'm still getting used to the idea that he actually wants to be with me." Kate falls silent for a few moments, picking at the remnants of her French fries. "Especially since I quit my job. I mean, that's what attracted him to me in the first place."

"No." Lanie sets down her fork. "You being a cop has nothing to do with his attraction to you. He loves you for _you,_ Kate. Because you're smart, and strong, and sweet, and sexy. You can ask anyone and they'll tell you that he'd still be head over heels, even if you'd never been a cop."

Kate nods at her friend's words. She knows that Lanie's right, but there's still a part of her that isn't sure. What she feels for Castle, how he obviously feels about her, she's never had this before. She's afraid of it ending; she's also a little scared of it being forever.

Lanie's phone buzzes and she mutters something under her breath when she glances at it. "I gotta go, sweetie," she says, dropping down money for her lunch and giving Kate a hug. She looks right in Kate's eyes when they pull apart. "I'm happy for you, Kate. Really, really happy."

Kate gives her another quick squeeze. "Thanks, Lanie. See you later." She sits for a few more minutes to finish her coffee, and she gets a text just as she's paying.

 _How's lunch?_

She grins. Castle. Impeccable timing, as usual. She types her response when she's outside.

 _Just finished, Lanie had to go in. What are you up to?_

 _Writing. I could use a distraction. Come over?_

Kate draws her bottom lip between her teeth as she considers. "Writing" usually means "doing everything I can think of besides writing," so she doubts the wisdom of her going to the loft to distract him further. Then again, he'd probably end up at her apartment if she didn't, and his bed is much more comfortable than hers…

She keys in her reply before she can change her mind.

 _On my way._

* * *

She can hear him talking even through the door, obviously agitated, and he gives her an apologetic smile when he lets her in.

"No, Paula. I said no. That's off the table." Castle walks back through his kitchen as Kate slips off her shoes, and he leans an elbow on the table, propping his forehead in his palm. "I told you, I don't want you to spin that anymore. No, I won't tell you why." A pause. "Because it's none of your damn business, that's why! I gotta go, Paula. Talk to you later."

Kate's standing at the end of the island, smirking. He looks so frustrated, his hair sticking up from where he's obviously been running his fingers through it, but she manages not to laugh at him. Instead, she taps a finger mindlessly on the countertop. "So, how's Paula?"

Castle lets out a low growl and drops his forehead to the counter. "Paula is…Paula. She's insisting on revisiting the 'free spirit bachelor' persona for the next book launch. I've told her no, but she's used to getting her way." He straightens back up and reaches for Kate, who comes willingly. "But I don't want that image. Not anymore. And I haven't wanted it for a long time."

Kate lets herself sink into his strong embrace, closing her eyes at the scent of his aftershave and detergent, and the faint smell of coffee. It's only been a couple hours, but she's missed him. God, she's missed him terribly.

Shit, Lanie was right. She has it bad.

Suddenly, his words to Paula sink in and her eyes pop open. "Why didn't you tell her about us?" she asks, pulling back so she can look up at him. "You said it's none of her business. But if you don't want that image anymore because we're together, she should know that."

"It's not that simple." Castle leans down to kiss her. "I've been on the Most Eligible Bachelor list for a long time now, and the minute it gets out that we're together, we'll get ambushed by media. They'll be all over you, Kate. Do you really want that?"

Kate furrows her eyebrows. "Well no, but we went out last week and it was fine."

"We went to places where I'm friends with the owners, and they were discreet. Plus, the book isn't coming out for a few months so I can fly under the radar. Come fall, when I have to do press, well, it's different." He takes her hand and leads her to his office. "I just…I know you like your privacy and I want to respect that."

Kate laces her fingers through his. "True, I do like my privacy." When he sits in his desk chair, she follows onto his lap, wrapping her arms around his neck. "But I also don't want to watch women fawn over you and ask you to sign their chests because they think they have a chance."

"They don't have a chance," he insists, shaking his head. "None of them ever will, because none of them are you."

Kate smiles and shifts to straddle his thighs. "Good." She kisses him, slow and deep, and feels the low rumble of his chest when she pulls away. "Because none of them can have you."

* * *

 _Thank you for the support! Also, Callie is a beta rock star._

 _The restaurant Castle takes her to is real, it's called Il Buco and the address is (ready for this?) 47 Bond Street in NYC. It's about a block and a half from the address used for Castle's building. It is, in fact, allegedly haunted by Poe's ghost. Feels like fate, no?_


	5. Chapter 5

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER 5**

* * *

It's a couple of days before she sees him again, opening her door with a small smile after his knock. She's been in a funk since last time she saw him, and she's grateful for the kiss he greets her with.

"Hey," she says quietly, fingers curled around the lapel of his jacket so she can pull him in for another kiss. "Did you finish it?"

Castle follows her into the kitchen, where she pours him a cup of coffee. "Yeah, sent it off last night. I'm sure there will be a lot of edits, but at least it's done. Another happy ending for Nikki and Rook." He smiles, accepting the mug with one hand.

"At least Gina's off your back now." Kate eyes his other hand, curled behind his back. "What are you hiding?" she asks, teasing him.

"Um, I got you something."

She raises an eyebrow at his tone. "Castle, what did I tell you about buying me stuff?"

He raises his free hand in surrender. "I know, you don't want me throwing my money around, even though it's my money to spend. But today's our ten day-iversary…"

"Our ten day-iversary?"

"Hush. Yes, our ten day-iversary. It's been ten days since we, you know, got together." He winks, making her chuckle. "And, I saw this, and thought of you." He brings a bag out from behind his back.

She wants to roll her eyes; he's definitely the first man she's been with that got her something for an anniversary of a number of days they'd been together. She wants to, but she can't, because he got her a throw pillow with an industrial-style gun design on it, and she absolutely loves it. It's something she would get for herself.

She grins in spite of her mild annoyance, thumbing the edge of the pillow. "Thanks, babe," she says, reaching out for his hand and pulling him for a kiss. "I love it."

He tugs at the hem of her shirt. "I'm glad." He kisses her again, slow and deep, drawing a moan from her throat when he pulls away. "I missed you," he whispers, his forehead resting against hers.

She closes her eyes and cups his cheeks, running her fingers along the stubble that's grown. "I missed you too." She lets him lift her onto the counter, and wraps her legs around his waist as he steps into the cradle of her hips. "Mmm, and I missed this."

He growls when she rolls her hips against his, causing him to jerk. "Shit, me too." He grips her thighs and carries her towards the bedroom.

* * *

"Hey, are you okay?"

Kate turns her head to look back at Castle, crowded at her back. "Yeah, I'm fine. Why?"

Castle props himself up on an elbow, his free hand tracing the line of her waist. "You were quiet during dinner."

"You wore me out today, babe." She leans up and brushes a kiss against his mouth, tries to deepen it to distract him, but he pulls back before she can. "Castle," she whines.

"I'm not just talking about dinner. Even when we talked the last couple days, you'd barely say anything." He sits up. "You're quieter than normal, Kate. What's going on?"

"Nothing."

" _Kate._ You know I can tell when you're lying."

She sighs and relents, crossing her legs in front of her as she sits up to face him, pulling the sheet up to cover her chest, knowing how he can get distracted. And this is a talk she wants them to have. "Do you wish I was still a cop?"

"What?" Castle shakes his head. "I want you to be happy. If you weren't happy as a cop, then you shouldn't be a cop."

Kate looks down at her lap, fingers plucking at nothing. "But…" She hesitates, but when Castle takes her hand, she looks back up at him. "You were first attracted to me because I was a cop. It's okay, but I want you to be honest with me. Don't just say it's fine if it's not. If you wish I was still a cop just say so."

Castle squeezes her hand and inches closer until their knees are touching. "I love you for you, Kate. If you're happiest as a cop, then you should think about going back. But that won't change my feelings for you. Whether you're a homicide detective or a street clown, I'd still love you."

Kate stares at their intertwined hands, at his thumb that's rubbing circles between her thumb and forefinger. "Castle...you keep saying those words. I'm sorry...I'm just not…"

"It's okay, Kate." He lifts her hand to press kisses to her knuckles. "You don't have to say it. I hope that some day you can, but not until you're ready. Okay?"

She wraps her arms around his neck, pulling herself onto his lap and settling her head in the crook of his shoulder. "Okay. Thank you, Rick."

He smiles against her forehead. "Always."

* * *

"Castle?"

He groans into her shoulder, snuggling closer to try and block the sound of his phone. "Five more minutes," he mumbles, the arm around her waist tugging her closer.

Kate pries herself from his embrace, warm and inviting as it is, and reaches over him to the nightstand. "You're ringing, babe," she says, handing him his phone.

Castle manages to turn over, plucking the offending item from her grasp. "Fine. Castle," he barks after clearing his throat.

She sees him sit up straighter, the broad plane of his back so tempting, but she simply presses a kiss to his shoulder blade and whispers "coffee" into his free ear before climbing out of his sinfully comfortable bed. They'd relocated to his loft thanks to the lack of food in hers, and she's starting to think that she should at least keep a couple extra shirts in his closet. She snags his shirt from the floor and fastens a few buttons while waiting for the coffee to brew, and by the time he pads out to meet her in the kitchen, she's pouring the drink into two mugs.

"Everything okay?" she asks, taking in his sleep-mussed hair and the slightly confused look on his face.

Castle accepts his mug with a smile and turns back to the bedroom, Kate at his heels. "Thanks. Um, I'm not sure. That was Gates."

"Captain Gates?"

"Yeah." He takes a few sips before pulling out clean clothes. "She asked me to meet her at a scene. I guess someone took some hostages at a dentist office, and the perp is insisting on talking to me."

Kate follows him to the bathroom and watches as he jumps in the shower. She's tempted to join him, but he's moving quickly, and she knows that if Gates is calling him, it's serious. The last thing she wants to do is keep her former captain waiting, and Castle seems to have the same idea, because he's in and out in minutes. "Do you want me to come along?" she asks, perched on the edge of the bed while he finishes getting ready.

He pulls his T-shirt on and shakes his head, running his fingers through his hair to tame it. "No, I'll be fine. I don't want it to be weird for you, being at a crime scene, not being able to do anything." He bends down to give her a kiss, squeezing her hip briefly before letting go. "They just want me to talk to her. I'll probably be back in a couple hours."

She doesn't start to worry until the clock ticks into the third hour and he's not answering his phone. She knows how long hostage negotiations can last; she'd been at the bank for most of the day when he'd been a hostage there. He's just a civilian, albeit a smart one, and really, if she was forced to have a civilian to be at a hostage negotiation, Castle wouldn't be the worst option. He'd kept his cool when he was a bank hostage a few months before; she's sure he'll be fine.

But after she reads a bit and eats some breakfast, she notices that it's getting even later, and she hasn't heard a word. Not from Castle, not from Gates, not from anybody. She didn't necessarily expect to hear from Gates unless something terrible had happened, but she is surprised at the radio silence from Castle.

 _How's it going?_ she finally texts him after she showers.

No answer.

Finally, she relents and calls Gates, but her former captain doesn't pick up either.

Now she's _really_ worried.

She's just about to call Ryan to find out where the situation is so she can go there herself when her phone finally buzzes.

 _Well, speak of the devil._

"Ryan," she says sharply, wincing at how it must sound. But dammit, she's starting to freak out. "Look, I can't talk, I'm waiting for-"

"It's about Castle," the detective interrupts, and Kate can hear street traffic in the background.

She tries to push down the panic that rises in her chest at the panic in his voice. "Ryan, what's going on? What about Castle?"

"He's been shot."

" _What?_ "

She's out the door before Ryan clarifies; Castle wasn't _shot_ shot, he'd been wearing a vest, but he'd been inside with the hostages and the suspect anyways.

Inside.

With a _murder suspect who was holding hostages._

God, he better be okay, because she might kill him for being an idiot.

She's at the scene in less than ten minutes, and gives Gates a quick greeting before being pointed in Castle's direction. He's sitting in the back of an ambulance, a paramedic holding a bag of ice to his bare chest, and even from several yards away, Kate can see the blossoming bruise. She's never been shot while wearing her vest (she only has the one bullet wound, she thinks with a fist clenched against her chest), but she knows several cops who have, and she's seen the bruising it can cause.

"Castle!" She finally calls his name when she's close enough for him to hear, and his face noticeably brightens when he sees her and offers a wave. She not-so-gracefully climbs into the ambulance and surges into him, wrapping her arms around his neck in a tight hug. "I'm so glad you're okay," she whispers, frantic.

Castle hugs her back, wincing when her chest comes into contact with his. "Me too," he manages to get out before he has to pull away.

Kate presses her fingers lightly to his chest, to the black and blue already starting to expand, and pulls back when he winces. "Shit, I'm sorry. Are you okay?"

"Yeah. It just hurts like a bitch."

"It will be sensitive to the touch for at least a few days," the nearby paramedic speaks up, and Kate moves to sit next to Castle on the gurney. "You'll probably see some residual bruising for several weeks." He leans against the open door and stares at the couple. "It'll be sore, but take some painkillers and you'll be fine."

Kate sighs in relief, dropping her forehead to his shoulder as her arm loops through his. "Thank God." Then the whole reason they're here hits her, and she smacks the same arm that she's holding onto. "Castle, are you an idiot, going in there? You could have been killed!"

Castle presses a kiss to her hairline. "It's fine, Kate. I was wearing a vest." He tucks a finger under her jaw and lifts so she's looking at him, and he tries to smile. "I'm sorry I worried you."

Kate scoffs. "Worried me? When Ryan called me the first thing he said was that you'd been shot. I almost jumped through the phone and strangled him." She leans into the palm cupping her cheek, closing her eyes briefly. "I felt helpless, Rick," she confesses in a quiet voice. "I hate feeling helpless."

Castle's thumb strokes her cheekbone. "I know, and I'm sorry that I didn't let you know what was going on. To be fair, though, it all kind of just happened."

"I know. These things can change in a second, remember?" Their eyes lock, and she knows that he's thinking of the same thing, of that crisp spring day not long before when a bank robbery had turned into so much more. After a few moments, she gives him a brief kiss before climbing out of the ambulance. "I'll be right back. Don't go anywhere."

Castle smiles. "I won't."

She finds Gates with the Hostage Rescue Team lead across the street, comparing notes on their debrief, undoubtedly analyzing what went right and what went wrong. Kate can definitely say what went wrong. They sent a civilian, a freaking mystery author, into a hostage situation, with no training whatsoever. They're damn lucky nothing _else_ went wrong.

Gates is the first to notice Kate. "How's Mr. Castle?" she asks, concern lacing her voice.

Kate crosses her arms. "He's fine. Can I talk to you?"

"Of course. Excuse me, gentlemen." Gates leads her to the edge of the crowd, where they can have at least some semblance of privacy. "How can I help you, Kate?"

"I want my job back."

Gates's hands land on her hips. "Run that by me again?"

Kate sighs. "I know I walked away, I resigned. I basically quit." She lowers her arms and shoves them in the back pockets of her jeans. "But this morning, I was at Ca...I was at home, and then Ryan called me, and I just felt helpless. I hated it."

"Look, Kate, you can't just walk back in and have your job back, I hope you know that. It's been almost two weeks. Your resignation paperwork is long since filed."

"Whatever I have to do, Sir. I just want my job back, however I can get it."

* * *

"Do you think you'll be able to get it back?" Castle asks a few hours later, after they've sufficiently celebrated his being alive. A couple times.

Kate raises her head from its resting spot on his stomach, where she'd settled, his chest too sore for even the lightest weight on it. "What, my job?"

"Yeah."

She shrugs and lays her head back down. "I have no idea. Probably. I'll probably have to go through the interview process again, maybe even recertify as detective. It would be worth it, though." She tightens her grip on his waist. "If anything, to keep an eye on you. Can't have you running off to crime scenes without me."

"Hey now," Castle protests, but it has no weight behind it. His fingers resume their trail across her shoulders. "To be honest, I missed you."

"I should hope so."

"That's not what I meant." He sits up with a grunt. "Shit, that hurts. Well, no, like that too. But I missed being at a crime scene with you, bouncing theory off each other. Our shared brain thing."

She chuckles as he wiggles his eyebrows; that is kind of their thing, isn't it? "Well, for what it's worth, I didn't like you being there without me. Not that you couldn't handle it, of course, but I like to think I deserve some credit for keeping you from doing too many stupid things." She uses his thighs as leverage to tug herself closer so she can reach his mouth. "Even if you do have a problem staying in the car."

He smiles against her kiss. "Well, you learned that telling me was pointless."

She hums in contentment, and they share a few more kisses before she softens them, eventually pulling away. "I love you," she says quietly, her nose nudging his.

His head snaps back. "You…"

"Yes," she breathes, feeling the weight of those words lift off her shoulders. "I have for a long time. Months, maybe years, I don't know. But at some point I realized that I'm completely in love with you." She leans back so she can look him in the eyes. "Something was holding me back from telling you, but today made me realize, again, that I could have lost the chance forever. And I'm sorry, you'd think after all these near-death experiences I would have pulled my head out of my ass a long time ago-"

"Whoa, Kate, hang on." Castle takes her hands, squeezing them for emphasis. "Your head hasn't been up your ass. You weren't ready to say it, and I get it. I didn't exactly pick a good time to tell you at first."

Kate gives him a watery chuckle, her eyes filled with unshed tears. "No, you didn't," she agrees. "But I knew then how I felt about you. I should have told you as soon as I had the chance."

Castle shakes his head. "Should, would, could. We can live in 'what ifs,' Kate, or we can move forward from here."

"So what do we do?"

"We stop apologizing for the past. We can't change what has happened. We can only take what we've learned and move forward. Deal?"

Kate smiles and leans into him for another kiss, pushing him to his back as she deepens it. "Deal."


	6. Chapter 6

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER 6**

* * *

"What do you want to do tonight?" Castle asks over breakfast a couple days later. They've spent almost every minute of the previous days together, still reeling over his close call with a bullet. They mostly stayed in Kate's apartment, but had taken a few strolls around the neighborhood, discovered a couple new restaurants.

Kate looks up from the pancakes he'd whipped up, washing her bite down with a swig of coffee. "Why don't we go see a movie?"

Castle pauses, his mug halfway to his mouth. "We could. Or, there's a new blues club that just opened in Brooklyn, it's supposed to be really nice. How about I take you there?"

"Oh. I guess that would be fine," Kate says after a moment, taking her half-finished breakfast into the kitchen. All of a sudden, she's lost her appetite. "Tonight, then?"

"Yeah." Castle follows her to the kitchen and grabs the dishcloth to help do the dishes. They wash in silence, slipping into the easy routine they've adapted over the previous two weeks.

They've always worked well together, Kate reflects as they clean up, and being in a relationship with Castle is better than she could have ever hoped. He's sweet and attentive, leaves her satisfied both inside the bedroom and out.

Well, mostly satisfied.

While they've gone out a handful of times, for the most part, they've been staying in. And she loves it; she's never been the type of woman who needs a lot of pomp and circumstance. She's perfectly fine with the low-key time they've been spending together.

But there's a part of her that wants more. She'll be back at work in six weeks, and she knows their free time together will decrease dramatically. So she wants to do more, now, while they can.

She's heard about the blues bar as well and does want to go, but she doesn't necessarily want to make a big production out of it. God, she probably sounds selfish. He's spent four years giving her space, waiting for her to be ready for this, for them. And she can't even get excited about going to a blues bar with him? What the hell is wrong with her?

"You okay?" Castle asks a few minutes later as he's slipping his shoes on.

Kate smiles and lifts herself to her toes so she can reach his mouth. "Yeah, I'm fine," she assures him. She let him pull her body into his, a low moan escaping when his hands start to creep south. "Mmm, tonight," she says when she pulls back. "I'll see you tonight."

* * *

"What do you want to drink?" Castle asks that evening, his mouth at Kate's ear so he can be heard over the crowd.

Kate shrugs, tugging him towards one of the few empty tables. "Nothing now," she practically has to yell.

"Sure?"

"Yeah." Her eyes scan the crowd, a habit she picked up quickly when she joined the police, one she can't turn off when she's off-duty. Much like her preference to sit facing the door or on the outside of a booth, that sense has actually grown over time, especially after she was shot.

She spots an empty table just a few feet away, but as they approach it she catches a familiar figure out of the corner of her eye. It's just the back of someone's head, but the long, dark hair belongs to a short, petite woman who looks suspiciously like…

Kate gasps when the person turns and she recognizes the profile. "Shit," she murmurs, and immediately changes course, turning towards the exit, Castle stumbling slightly at her sudden movement.

"Kate, what-"

"Gates," she hisses through her teeth, and spares a glance behind her to make sure her boss hadn't seen them. She pushes him out the door, and they're almost to the end of the block before she feels comfortable stopping.

"What the hell, Kate?" Castle asks as soon as they stop, both panting slightly from the rushed pace Kate had set.

"Gates was there."

"So?"

"So, we can't be seen together."

Castle just stares. "Okay, I need a little more."

Kate sighs, frustrated that he's not following her line of thinking. "The NYPD has a strict policy against coworkers dating, especially partners. If Gates finds out, she'd kick you out. We wouldn't be able to work together anymore after I'm back."

"But Lanie and the boys know. She's bound to find out at some point."

"They like having you on the team, Castle," Kate explains, throwing her arm out for a cab. "They won't tell her. But Gates was there, at the club, and she almost saw us. She'd start asking questions, and you're a terrible liar, and she'd figure it out almost immediately."

"Kate." Castle pulls her arm down, his hand enveloping hers. "First of all, I'm not a terrible liar." He keeps talking before she can interrupt him. "I don't think Gates would care. But, since you do, I'm okay with it." He leans down to give her a kiss. "Where should we go instead?"

Kate shrugs even as she lists into his body. "Mmm, your place? We can stay in, won't risk running into anyone we don't want to see?"

Castle throws his arm up to hail an incoming cab. "Sounds like a plan."

* * *

The next evening, they're at her apartment making dinner when Castle brings it up again.

"Let's go back tonight," he says suddenly, interrupting the easy silence they'd found themselves in.

Kate looks up from the garlic she's diving, eyebrows furrowed. "Where?"

Castle sets his knife down and quickly washes his hands from the chicken he'd been slicing. "The blues club." He steps closer when Kate starts to shake her head. "Come on, Beckett, please? I've been really looking forward to this place. And even you have to admit it looked really great."

"But Gates-"

"Was there last night," he interrupts, sliding his arm across her waist. "I doubt she'll be there two nights in a row."

Kate sighs, her body leaning into him almost unconsciously. "Okay, let's go again. It did look like a nice place."

Castle kisses her cheek quickly, then goes back to the chicken. "It'll be fun, I promise."

They eat quickly, and get to the club shortly before the band goes on; there aren't any seats, so they get drinks then stand in the back. Kate doesn't mind, because it gives them the opportunity to slip away if they see Gates again. Gates is nowhere to be found, though, and after a few minutes Castle nudges them towards a table that opens up.

Kate knows she's being ridiculous; Gates won't be here two nights in a row, and even if she is, who cares? So what if Gates knows that she and Castle are dating? Technically, Castle's not paid, so he's not an employee, but she doesn't think Gates will see it that way. So, better safe than sorry. So she tries to relax and enjoy the music, her boyfriend's warm arm across her shoulders.

She tries.

But as the minutes pass and her second drink starts to course through her system, she starts to feel nervous, on edge. Her heel is tapping against the floor uncontrollably, and she can feel her chest tighten, the scar in the middle start to throb. Her heart starts to pound, and she can hear her blood rush through her veins, deafening in her ears.

The people seem to be getting closer, the walls closing in, and she can feel eyes on her, all around her. She knows that music is playing, but all she can hear is the bass, echoing her heartbeat in her ears. Eyes all over her. She can't breathe. She can't speak.

 _Oh God. Not here. Not now._

She gropes for Castle's free hand and finds it in his lap, grabs his fingers tightly. She's making every effort to keep her breathing regular, but he must sense her panic when she touches him because he tightens his grip on her shoulders and leans in close to her ear.

"Are you okay?" he asks her as quietly as he can in the loud club, but making sure she can hear her.

She can only shake her head while trying to blink back the tears blurring her vision.

 _Fuck._

Castle pushes his chair back and helps her stand. "I'm taking you home."

She just follows him, lets him lead her outside, where he hails a cab. "Castle…" she manages to get out, barely a whisper. She lets him draw her into his arms, closing her eyes as she sinks into his chest.

He opens the door when the cab stops in front of them and gently prods her into the backseat, gives the driver her address once he's in. He hasn't broken contact with her since the club. "It's okay," he murmurs in her ear, his hands tracing her spine.

"I'm sorry."

"No, Kate. Don't be sorry. Don't ever be sorry, not for this."

He continues his whispered reassurances for the entirety of the ride, pausing only to pay the driver and lead her into her building.

She barely notices when they step onto the elevator, or when he gets her keys from her purse, or even when he leads her inside and to her couch. But before she knows it there's a blanket over her shoulders and a steaming mug of tea in front of her, and she glances up to where he's standing.

He looks worried, obviously, but Kate thinks she sees a trace of something else within the blue as well.

She disappointed him. He wanted to stay at the club. He'd been looking forward to it. She doesn't blame him, she wanted to stay too. But she couldn't. She just couldn't.

She's disappointed in herself.

"I'm sorry," she says again when he turns back towards the kitchen. "You should have stayed, I would have been okay."

"Kate," he breathes, taking the few short strides so he's sitting next to her on the couch. "No way was that going to happen. You could barely speak, let alone walk on your own power." He takes her hands in his and shifts closer. "Do you have them often?"

Kate looks up, startled. How can he ask her that, when he knows…oh. He doesn't know. Right.

"I used to," she admits, reaching out to caress his cheek when his face falls. "They started after I was shot. That's one reason I went out to my dad's cabin. When I was here, every little thing would set one off. A siren, a car door slamming, even someone shouting on the street."

"Shit, Kate…"

Kate drops her hand to his shoulder and gives it a light squeeze. "That's why I didn't call you that summer, Rick. I couldn't. I pulled up your number so many times, but then I'd flash back to that cemetery, and I'd spiral into another one."

"If I'd been there…"

"It still would have happened. Rick." She takes his face in both hands and forces him to look at her. "I needed to be alone that summer. And I needed to do therapy when I came back. I did what I did to heal, not just to be ready for a relationship with you, for this, but to be whole again."

"And you…" Castle clears his throat and covers her hands with his. "Do you still have them? The panic attacks?"

Kate nods. "Sometimes. It's been awhile. I haven't had a bad one since that sniper case a few months ago."

"What triggers them?"

"Um, this time, it was the crowd. I was stressed about the possibility of seeing Gates, and I kind of felt suffocated by everyone, and the music. Honestly, if it wasn't for last night, I probably would have been fine."

The moment the words come out of her mouth, she wishes she could take them back. His face falls, but before he can say anything her arms are around his neck and she's sliding onto his lap, and feels his arms envelop her immediately. God, he probably feels guilty for taking her out, especially when she'd been so hesitant.

"We're staying in for the foreseeable future," he murmurs into her hair. "Movie marathons and takeout until you're back to work."

She can't help but smile, her face buried in his chest. This sweet, sweet man. He'd do anything to keep her happy. "Let's just take one day at a time, babe."

* * *

She wakes the next morning as he's setting coffee on her nightstand; smiling, she sits up and takes a hold of the mug as Castle settles in beside her again. "Morning," she says after a sip, accepting his kiss on her cheek with a smile.

Castle grins. "Morning. Did you sleep okay?" He punctuates his question with a wink, which makes her giggle.

"You already know the answer to that question." Neither of them had slept very much; after cuddling on the couch for awhile, they'd relocated to the bedroom, where Castle had insisted that he prove just how productive they could be while "staying in." It had been slow, and loving, and tender, but she definitely needs this coffee now.

They sit in silence as they drink their coffee, Kate dropping her head to his shoulder when she finishes. "Can we stay in today?" she asks quietly after a few minutes.

Castle cranes his neck so he can press a kiss to the top of her head. "Of course. I was serious last night, we can stay in for the rest of your time off if you want."

Kate giggles. "That's five weeks, Castle. I don't need to be in seclusion just because I had one panic attack. I just want to stay in today."

"Okay. Netflix?" When Kate nods against his shoulder, he scrambles out of bed and pulls on his boxers.

Kate watches as he looks around, presumably for the rest of his clothes, since he pulls on his t-shirt as soon as he finds it. "What are you doing?"

He glances at her while pulling on his pants. "Well, we're going back to my place."

"Why?"

"Why not?"

Kate just stares, clutching the sheets around her. "Is there a reason you don't want to watch here?" she retorts sharply.

"No, but we can watch in my theater room, snuggle on the couch. It'll be more comfortable, roomier."

His words cut right to her core; she knows he doesn't really mean it, is only thinking about this particular day. But he's unknowingly voicing every fear she has about this relationship, about them. That she's not good enough. And if her couch isn't good enough for him, then is she?

She feels a prickle behind her eyes, but she refuses to acknowledge it. She won't cry. Not in front of him. Not about this. "So what you're saying is my apartment isn't good enough for you?" she shoots back, defensive. If they're going to have this fight, she's going to come out swinging.

Castle finally stops and looks at her. She's stiff, arms crossed, eyes following his movements. She hasn't moved an inch. "That's not what I said."

Kate huffs. "That's definitely what it sounded like."

"Kate-"

"No, forget it." Finally she moves, slithering out of bed and immediately pulling her robe on. "Look, we've been spending a lot of time together. Maybe we should take a day or two, do our own things. I'm sure Paula would love to talk to you about the book publicity. You can work on convincing her not to do the 'fun bachelor' persona." It's a low blow, she knows, and judging by the way his jaw hardens he's also thinking of their previous conversation.

"Kate."

She crosses her arms again and holds his stare. "I have to catch up on laundry, anyway." It's weak, and she can tell by the way he narrows his eyes slightly that he doesn't believe her. But she holds her ground.

Finally, Castle sighs, his shoulders slumping. "Okay, fine." He grabs his wallet from the top of her dresser and stuffs it in his pocket. "I'll let you do your thing. Talk to you later."

She doesn't follow him out, doesn't move, until she hears her door slam. She goes through the motions of getting ready, then, takes a long shower. She wants another cup of coffee but not his, not the stuff he always seems to make perfectly, even in her crappy coffeemaker.

Her fingers itch to text him, call him, to apologize for snapping at him. But she doesn't. Maybe she's blowing it out of proportion, but his words hurt. Finally, after she sorts her laundry (she wasn't lying about that), she can't take it anymore. It's been a few hours now. Maybe he texted her. Maybe he called. So she grabs her phone to check; she hasn't heard it go off, but she's been busying herself, so she could have missed it.

Her heart sinks when she sees her empty notifications.

Nothing.

No missed call. No voice mail. No text. Nothing.

 _What have I done?_

* * *

 _AN: the scene with Gates was inspired/prompted/requested by_ _prosemeds on Twitter a couple months back. I hope I did it justice!_

 _I apologize for the wait with this chapter, hopefully you won't have to wait as long until the next one. Thank you all for your support!_


	7. Chapter 7

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER SEVEN**

* * *

She doesn't let herself mope for very long. By this time it's nearing dinner, and she'd been so upset she skipped lunch, so her stomach is starting to protest. But she doesn't want to end this day without making up with Castle, apologizing to him.

If he'll talk to her, of course.

His lack of communication hasn't gone unnoticed, either. It weighs heavily on her mind, the fact that they fought several hours before, and he hasn't reached out to her.

But she's the one that overreacted, she's the one that needs to fix this. He waited for her, pursued her, for _four years_.

It's her turn. It's been her turn for a long time.

She slips her phone into her pocket and grabs her keys; she'll call his favorite Thai restaurant on the way to his loft, bring him dinner as a peace offering. It's not much, but it's something.

She's at his building in a half hour, after the brief stop to get their food, and waves at the doorman before heading to the elevator. While she waits to arrive at his floor she takes out her phone, considers calling him, but slips her phone back into her pocket without dialing.

No, she'll just show up, surprise him. It will mean more.

Her eyes are down when the elevator pings its arrival, and she's about to step forward when-

"Kate?"

Her head snaps up to see Castle standing in front of the elevator, surprise written across his face, yet a smile tugs at the corner of his lips. She hangs her head, allows her hair to frame her face, cover the flush she's sure is creeping onto her cheeks. "Hey," she says quietly, drawing her bottom lip between her teeth.

Castle throws his arm out to catch the doors when they start to close, and he steps aside to let her walk past him into the hall. "Hey. What are you doing here?"

Kate reaches out and takes his hand. "I should have called, you were on your way out."

Castle smiles and looks down at her.. "I was kinda coming to see you." His eyes drift down to her other hand, holding her purse and a plastic bag. "You brought food?"

"Um, yeah." Kate lifts the bag. "I got dinner at the Thai place. I hope you haven't eaten yet?"

Castle chuckles and lets them into his apartment. "Great minds," he says quietly, squeezing her hand before letting go and taking the food. "I was about to call that Italian restaurant you love and bring food to _you_."

Kate follows him into the kitchen and wraps her arms around his waist from behind, rests her cheek against his shoulder. "I'm sorry," she says quietly, her lips brushing against his sweater.

Castle turns in her arms and wraps his around her back, kissing the top of her head. He takes a deep breath, rests his cheek on top of the spot he kissed her. She's wearing sneakers, so their height difference allows her to tuck her head right under his chin. "I'm sorry too," he murmurs against her hair. "I realized too late how it sounded, I didn't mean-"

Kate takes a step back so she can look up at him, look into his eyes. "No, I overreacted." She starts walking them towards the living room, follows him onto the couch. "I love you, Rick. I love being with you, spending time with you." Her hand lands on his knee, thumb rubbing circles over his patella. "But I'm scared. I've never felt this way about anyone before. I'm so scared that this won't last, that I'll inevitably screw it up, that I'll lose you over something stupid. And I just hope that I didn't do that this morning."

"No, Kate. You didn't screw anything up." Castle covers her hand with his. "I know we haven't been…romantic…for very long. But I've loved you for a long time. You've been my best friend for years. I'm not going anywhere, okay?" He reaches up to cup her jaw, brushes his thumb over her temple. "I'm in this, okay? There isn't anything you could do to get me to stop loving you."

"I just…what you said, how you assumed that we'd just come here to watch movies," Kate continues after a moment, "it felt like you were saying my place isn't good enough, that it's not as good as yours. And I know my apartment isn't as big, my mattress and couch aren't as comfortable, but it's still my home."

"Kate…"

"You don't need to impress me, Rick," she interrupts, and when he stills, she knows she hit a nerve. He spent so long as a playboy, throwing his money around to woo women, and she has a feeling that that part of him is still deep down inside. "You already have me. You could be living in a 500 square foot studio in Queens and I'd still love you just the same. Okay?"

Castle takes a few moments to respond, his throat bobbing as he swallows, his eyes shimmering with unshed tears. "It's not often that I'm rendered speechless," he finally gets out, his voice cracking.

Kate chuckles and squeezes his hand. "Well I guess there's only one thing we can do," she responds, tugging herself onto his lap and bracketing his face with her hands. She kisses him deeply, the work of her tongue drawing a moan from deep in his chest, her hips rolling as his hands travel down her sides. Before his hands land at her hips, though, she pulls away and stands with a smile. "Eat before the food gets cold."

She shrieks when Castle catches her in the kitchen, grabbing her hips and pulling her back into him. His lips land at her neck, and he nips at her nape, soothes the sting with his tongue. "Don't," she protests, but it's weak, and the nudge back with her shoulders carries no weight behind it.

"Why not?" he mumbles against her skin. He's moved to her shoulder, having nudged the loose collar of her t-shirt aside, and his teeth scrape against her skin. "Who's gonna see it? Not gonna leave any time soon."

Kate moans and turns in his arms, loops hers around his neck. "Thai does reheat well," she concedes, allowing him to grip her thighs and hopping to help him guide her onto the counter. She pushes the food aside as she leans back, Castle above her, his hands pushing up her sweatshirt. "Here?"

Castle peppers kisses along the skin he exposes, drawing a moan from her lips when he hits especially sensitive spots. He pauses to worship at her mouth, kissing her slowly, getting lost in her taste until her hands start to wander. Grinning against her lips, he helps her unbuckle his belt, chuckles at her frustration when she has trouble with his jeans. "Here."

* * *

She remembers to put the food in the refrigerator after round one, even while he's heavily encouraging her to move to the bedroom. They end up in Castle's office, when his insistent hands and mouth finally get to her and she straddles him in his desk chair. It isn't until they're sprawled on his bed, sweaty and sufficiently sated after round three, that she manages to form complete words again.

"Make up sex," Castle grunts, his arm flung over his eyes and his legs hanging off the edge of the mattress.

Kate chuckles, low and hoarse from overuse; she hadn't exactly been quiet, and she knows she'll feel it later. "Best kind," she agrees. Her head is on his stomach, facing him; she lifts a hand to brush her fingertips over the bruise on his chest. "Does it still hurt?"

Castle jumps at her touch, then pushes himself to his elbows and drags himself to lean against the headboard. He reaches for Kate, smiling when she follows and curls up against his side and lets out a low hum. "A little," he admits.

"Want some Tylenol?"

"No, it's alright. I can manage." It's been a few days, and the bruise has evolved to a kaleidoscope of dark purple and yellow, but he still yelps a little when she presses an experimental touch to his skin.

"Shit, I'm sorry," Kate apologizes, and she brushes her lips against his sternum before resting her head on his shoulder.

They lie there for a few minutes in silence, the only sound in the room their breathing and the light hum of the air conditioning.

"Are we okay?"

Castle's words startle her back into consciousness; she'd almost fallen asleep, but he sounds so concerned, she lifts herself to her elbow so she can look him directly in the eye. "What do you mean?"

"What you said earlier, about how you're afraid you'd screwed this up. Us." Castle shifts so he's facing her. "Kate. I could never walk away from you. I've tried, God knows I've tried. But I couldn't. I don't deserve you." He cups her cheek and leans forward to dust a kiss against her mouth. "I love you, Kate. I will always love you."

Kate swallows around the lump in her throat and returns his kiss. "Hmm, I love you too."

"So we're okay?"

"Yeah, we're okay." She smiles against his mouth. "I think you fucked the insecurity right out of me."

Castle rolls on top of her, his hips settling between hers. "I don't know, you don't sound very sincere," he teases.

Kate groans. "God, Castle, I can't. Not yet."

Castle winks. "Are you sure about that?" He nips at her jaw, his tongue flicking out to soothe the sting. He stops before she can respond, before she can arch into him, and pushes himself off her. "Dammit, I can't yet either. You're going to be the death of me, woman."

"What, suddenly you can't keep up?" Kate pokes him right under his ribs where she'd recently discovered his ticklish spot, but snuggles into his side when he tries to squirm away.

"Oh I'll keep _up,_ all right. Just give me a couple hours."

Kate grins against his chest; she's still mindful of the bruise, but it's definitely smaller, and looks better than before, so she feels good about laying with her head on his chest again. She feels him move, and helps him pull the sheet over them. She's still warm, but she knows as soon as her body temperature finishes going down she'll be grateful for both the sheet and the human heater next to her. Because if there's one thing she's learned from the few weeks they've been together, it's that Castle is warm. As long as she's by him, she definitely won't be cold ever again.

The thought startles her from the edge of sleep, even as she hears Castle's breathing even out, telling her that he's fallen asleep.

 _Ever again._

She hasn't thought about it in so many words, but deep down, she thinks that Castle may be it, her one-and-done. She's had serious boyfriends, sure, Will had even sort of proposed when trying to convince her to move to Boston with him. But she's never felt the way she feels now. Around Rick she's safe, she's happy. She's home.

 _Oh God._

If she's honest with herself, she's known it for a long time. Since he tried to save her from a bullet. Since he flew to LA with her. Since he punched out a skilled assassin for her. Since he dropped a hundred grand for the chance at her mom's killer.

Since he looked at her mom's case.

Because as mad as she was, as unforgivable as it was for him to look at her mom's file after she's told him it was off limits, she knows that he'd only sped up an eventuality. Sooner or later, Kate would have fallen down the rabbit hole again.

Raglan would still have come to her after his cancer diagnosis, and that would have been it. It would have been the push to pull her back in. And without Castle…

Kate feels a shudder wrack through her body and she grips Castle tighter, feels his arm tighten around her shoulders, even while he sleeps.

She won't think about what could have been. Not right now, not tonight, not while she's lying in the arms of the man she loves. So instead she sighs in contentment, closes her eyes, and eventually falls asleep.

* * *

"How would you feel," Castle asks the next morning, "about going out of town?"

Kate cocks an eyebrow, studying him over the bowl of grapes he's just set in front of her. "Out of town as in, go on vacation? As a couple?"

"Yeah." Castle wipes his hands on a dish towel and slides onto the bar stool next to her. "The Fourth of July is coming up, and usually by now Mother's at the Hamptons organizing a big party. She's not here this year, obviously, but I think it would be nice to get out of the city for a little while."

"I don't know, Castle." Kate leans into his side while she pops a grape into her mouth. She chews slowly, considering, even though every fiber of her being is shouting at her to yes, yes, absolutely say yes. She can't help but think of another offer just two years before, when he'd invited her to his Hamptons house for Memorial Day weekend, an invitation that had been declined when his ex-wife had shown up to collect him. "I mean, just the two of us, together 24/7? Here, we can retreat to our own apartments if we have to."

Castle nudges her with his shoulder. "Ah, but Kate, you haven't seen my house. There's definitely enough room to retreat if needed." He pauses for a few moments before pulling back so he can look at her. "Are you saying that you'd need space? Maybe this isn't a good idea, we can wait a few months before we go away together-"

"Castle." Kate brings a hand up to cover his mouth, shutting him up. "I'd love to go away with you, and the Hamptons sound wonderful. I've never been up there."

"Really? You grew up with two lawyer parents and you've never been to the Hamptons?"

Kate shakes her head. "No, they had to rub elbows with the higher ups enough in the city. When I was little we bought a cabin in the Catskills, a couple hours north. It's right on a lake, so it's where we'd go to escape, for at least a week or two in the summer when the heat here was too unbearable." She knows she probably has a goofy smile on her face, but her memories from a time long ago, when she didn't know just what pain felt like, make her nostalgic.

"Is it where you spent last summer?"

She's brought out of her reverie by Castle's question, not unexpected, but not anticipated, either. It's hard to read the look on his face; there's something etched in his features that's close to anger, but the same fire she usually sees in his eyes when he's mad is missing. He almost looks...disappointed. Resigned.

"Yeah." She supposes this talk was coming. They've spoken about that summer in bits and pieces, but she's never fully explained what happened, why she had to leave. Why she didn't call. "Castle-"

"You don't have to explain," Castle interrupts, taking her hand and squeezing. "We don't have to have this talk now, Kate." He leans forward and and brushes a kiss against her forehead. "Would you be interested in coming to the Hamptons? I know it's kind of my turf, but it's really something to see on the Fourth. And I know it's still a few weeks away, but we can go when it's closer-"

"Rick." She uses his hand as leverage to pull herself closer to him so she can kiss him on the mouth, once, twice. "Let's go next week, and stay through the Fourth. I'd love to take you to the cabin, too, but my dad's there right now, and he likes his space." She kisses him again, deeper this time, and tucks her hands in the back pockets of his jeans, squeezing his ass lightly. "Take me, Castle."

"To the Hamptons?"

"That too."

* * *

 _A/N: Your response to this story blows me away. Thank you readers and also the always wonderful Callie for her brainstorming/betaing!_


	8. Chapter 8

**CHAPTER EIGHT**

* * *

Kate can't stop fidgeting in the elevator.

It's ridiculous, she knows that without a doubt, but no matter how much she tells herself to calm down, she finds herself fidgeting. Wringing her fingers together, adjusting the strap of her messenger bag, shifting her weight from one foot to the other. And she's checked her bag at least a dozen times since leaving home, making sure she had everything she needed. Tickets, check. Hat, check. Sunglasses, on her head. She even has a gift for Castle for their date.

She finally stops when knocks on his door; he must have been waiting, because it opens almost immediately. "Hey," she says with a grin, stifling a laugh. "Nice hat."

Castle tugs at the brim of his baseball cap, blue and adorned with the bright orange Mets logo, and pulls her inside. "Thanks. I figured that being with you, I should probably have _something_ to show my colors." He winces when the brim knocks against Kate's forehead when he tries to lean down for a kiss. "Shit, sorry."

Kate chuckles. "Don't worry about it." She runs her fingertips through the exposed hair below the cap, tilting her head so she can kiss him without the hat getting in the way. When they part, she lifts the brim so she can see his eyes better. "I'm not sure the baseball hat is the best look for you, babe."

"Hey now," Castle argues, mock hurt curtaining his features. "I can make it work."

"Yeah, okay." Kate's fingers tug at the hem of his blue t-shirt. "I have something for you," she admits, reaching into her bag to stop herself from sliding her hands beneath his shirt. They don't have time, not if they want to get to the game early enough to take in some of the stadium before first pitch.

Castle's eyes brighten, making him look like a kid on Christmas morning, and Kate can't stop the giggle from escaping her lips. "Really?" he asks, his voice light, excited.

Kate brings out the plastic bag, grinning at him when he practically flings it across the room when he takes the item out. "Yeah, really." She tugs at her own shirt, her matching Dwight Gooden jersey shirt. "I thought maybe we could match. You know, like one of those sickening couples with matching outfits that we make fun of. And I know it's not a real jersey, but-"

Castle interrupts her with a kiss, his arms tight around her back, swallowing her moan when his tongue slips between the seam of her lips. They part when air becomes a necessity, and he gives her a quick peck before pulling back, a grin on his face. "I don't need a real jersey," he breathes, his forehead against hers. "I love it."

"Good," Kate whispers against his mouth. "We should get going. You ready?"

"Yeah." He switches shirts, then grabs his wallet and keys and shuts the door behind them. They walk hand in hand to the subway, making their way through the crowd, riding in relative silence. A transfer and second ride later, they arrive at Citi Field in Queens, where they disembark with the other riders, most of them dressed in Mets shirts, jerseys, and hats.

"Hold up," Castle says suddenly, tugging Kate's hand to pull her into his side. His phone is already out, the camera on selfie mode.

Kate rolls her eyes at first, but when he presses his lips against her cheek with a loud _smack,_ she giggles, leaning into him almost unconsciously as he takes a few pictures of them, some goofy and some not, the stadium in the background. "I want to show you something," she says after a few clicks of the shutter, unwrapping her arms from around his waist.

She leads him partway around the front, eyes glancing towards the ground every few feet, until she finally lets out a triumphant cry and stops. She pulls him to crouch down with her, and points at the adjoined bricks on the sidewalk. One is adorned with "For Mom, Love Katie," while the other simply says "Vincit Omnia Veritas."

"Kate…" Castle whispers, his fingers reaching down to trace over the words.

Kate just watches him; since the stadium opened a few years previously she'd gone to a handful of games, both with and without her dad, and she always stopped at the brick, even for just a moment. "They sold these bricks to raise money for charity," she explains, the world around them fading even as people have to walk around them. "Dad and I came to more games than she did, but she did still love to come, loved the game. So we bought a couple bricks. For her memory, you know?"

Castle stands and pulls her up, wraps his arms around her in a tight hug. "I love you," he breathes into her hair, his face in her neck.

Kate smiles against his neck. "I love you too." She pulls away and cups his cheeks. "Come on, let's go inside." She digs the tickets out of her bag and hands one to Castle, her hand still tight in his, leading him through the lines of people already waiting to go inside, to wait at the main gate. It's a couple hours before first pitch, so the crowds aren't as congested as they will be closer to game time, but Kate had wanted to get there early.

She leads him through the turnstiles and into the large rotunda, and she stops to get a program and scorecard. She smiles at the amazed look on Castle's face as he looks around, and reaches her hand out to him. "You hungry? There are some killer tacos here."

Castle's face lights up. "Hell yeah, but aren't hot dogs the required food?"

Kate chuckles. "Whatever you want, babe." She uses their joined hands to lean up and steal a kiss. "My treat."

They take their time getting to their seats; Kate usually sits in the upper level seats when she comes by herself, just as happy in the cheap seats as the field level, but she's splurged for their date. Their seats are on the field level, close to the home plate entrance they'd come through, but they wander around the stadium until it gets closer to game time.

They settle in their seats with their food with just enough time to eat before the National Anthem and ceremonial first pitch, and by the time the game starts, Kate has her scorecard on her lap, her left arm looped through Castle's right.

She knows that Castle has never liked baseball. She'd seen the trepidation in his eyes when she'd first suggested they go to a game, and even when she'd brought it up again the previous weekend, he'd hesitated. But he claimed that regardless of what they were doing, he wanted to spend time with her. And she loved it, so he wanted to join her. Nevertheless, Kate knows that to someone who knows nothing about it, baseball can be rather boring. So she explains the game as it passes, answers the questions Castle has, trying to keep it interesting.

As the game enters the second hour, and Castle goes to work on his third beer, however, she can tell his attention is starting to wander.

His hand, too.

The hand that had been circling her knee, allowing him to lean close for a question or a kiss, begins to inch higher. It's subtle at first, high enough so his pinky can sneak under the hem of her shorts, but low enough to be decent. But the heat of his palm scalds her and makes her shiver at the same time, and she wonders how she'll ever survive his next book tour if she can't even go a day without touching him.

It's when he leans in far enough so his nose brushes her cheek that Kate feels goosebumps erupt along her arms. He simply asks if she wants another beer, but between his deep voice and his breath wafting over her cheek, she's had enough.

"No," she breathes, grabbing her bag and stuffing her scorecard inside. "Let's get out of here."

"But we'll miss the rest of the game," Castle teases, a glint in his eye, his grin widening when she takes his hand off her leg and laces her fingers through his.

"I don't care." She shoves him out of his seat and follows him up the stairs to the concourse, their hands letting go only when they stop at their respective restrooms before exiting the stadium.

With the weeknight game in progress, and most late commuters on subways going the opposite direction, the trains are relatively crowd-free. They sit next to each other, and while Kate tries to keep enough distance so she's not tempted to risk public indecency, Castle slips his arm around her shoulders and pulls her flush into his side. His thigh is hot against hers, and the heat from his skin warms her inside and out, sends her blood singing.

"Wanna do something here?" Castle murmurs when they're close to the Times Square station, his lips brushing against the shell of her ear. "Watch the rest of the game in a bar?"

Kate shivers and knocks her temple against his chin. "Fuck no," she shoots back, her fingers itching to slip under his shirt, his shorts. But she forces herself to simply take his hand when the train stops and lead him to the platform to catch the subway that will take them back to his place. No, she can read about the game later. But she needs to get her hands on her boyfriend _now._

* * *

They're having a relaxing breakfast together a few days later when Kate brings it up. She'd been thinking about it for awhile, since before she and Castle had even gotten together, if she was honest with herself. But it had never been the right time, and over the previous couple of years, with their relationship evolving, Kate hadn't wanted to potentially cross lines that neither of them had even acknowledged yet.

But now, she knows. She knows that this man will be part of her life for the rest of it, until the day she dies. And it scares her, sure, but she's also excited, invigorated. She wants to share every part of her life with him, and that includes the bad, along with the good.

"Do you have any plans for today?" she asks as she finishes her food, as he's taking the last few bites of his own.

Castle shakes his head around a mouthful of eggs, waiting to swallow to answer. "No, why? What do you have in mind?"

She stands and takes his plate, and he follows her to the sink. "I want to take you somewhere," she answers, not looking at him, but focusing on the plates as she washes them. "Show you something."

"Okay." Castle dries the plates and puts them away, then tugs her into his arms. "Now? Or later?"

"Um, now." She pulls away so she isn't tempted to give into the part of her that just wants to say _fuck it_ and take him to bed. So instead she lets go of his hands and heads towards the door, slides on her sneakers, and he follows. As always, he follows.

"Where are we going?" he asks as they take the stairs downstairs, Kate bouncing slightly on the balls of her feet as they go outside.

Kate hails a cab, gives the driver an address. "Just...somewhere." She's being coy on purpose, but she hears Castle's sharp intake of breath when the cab turns into the entrance of the cemetery.

"Kate…" he whispers, but she pays the driver and takes his hand as they start up the small hill in front of them.

"Come on, babe," she says quietly, tugging on his hand. They walk up in silence, a path that Kate had memorized long ago, that she could do in her sleep. _Has_ done in her sleep, in her dreams. They finally come to a stop in front of the headstone.

It's simple, and she stays back a few feet as Castle takes a step forward, rests his hand on top of the stone. His head is down so she can't see him, but she hears the sniffle, sees the slight shake of his shoulders. She'd come here just a few weeks before, the morning after her and Castle's fight about the case, the morning before she'd gone after Maddox and almost paid for it with her life.

But this is the first time she's brought someone besides her dad; even Lanie hasn't been here, or Will, even when they were serious. No, she usually comes alone, when she needs to feel grounded, sense the direction or advice that her mom would give if she was alive. Sometimes she talks out loud, in whispers, of course. But usually she just stands still and listens.

After a few minutes she approaches Castle, places a tentative yet supporting hand on his shoulder. He startles and turns, and she reaches up to brush her thumb over his wet cheeks.

"We should have brought flowers," he says, his voice breaking. "I feel like a terrible boyfriend, doesn't even bring anything when I meet a parent."

Kate gives him a watery smile. "I usually don't," she admits, feeling her face flush. "I will on special occasions: Mother's Day, her birthday, the anniversary of...you know." She tucks herself into Castle's side when he extends his arm. "Dad brings flowers more than I do. He comes more often, too. I just...he likes to be here, that physical presence. I...well, I don't need it as often."

Castle wraps both his arms around her, pulling her into his chest. "I'm so sorry, Kate," he murmurs into her hair. "I mean, I know what it's done to you, how you've suffered, but I just...I wish this hadn't happened."

"Me too," she agrees, but after a beat she rocks back on her heels so she can look up at him. "If it hadn't, though, I wouldn't have become a cop. And we might not have met. So, if there's a positive to take from this," she adds, motioning to the headstone, "it's that it, eventually, brought me to you."

"Literally." He pulls her into his side again. "I wish I could have met her."

Kate smiles as she tucks her head under his chin. This is why she wore her sneakers: when she's in his arms like this she feels safe, secure. Like he can protect her from anything, shield her from all the pain in the world. "Me too," she admits, her hand sneaking under his collar to rub her thumb against his clavicle. "She would have loved you, Rick."

"Yeah?"

"Are you kidding me? You two would have conspired to get me to go out with you a long time ago. Hell, she would have paid for our first date." She feels Castle's chuckle as much as she hears it, and she smiles against his shirt, takes one last look at the headstone. _I love you, Mom._

"Come on, Castle," she finally says, pulling away and taking his hand. "I'll let you buy me lunch."

* * *

 _A/N: I am so, so sorry for the long wait with this one. I wrote myself into a block with this chapter and had trouble getting around it. There will not be as long as a wait for the next chapter, I promise. Thank you for your continued support, and as always, to Callie for putting up with my incessant complaining about how hard words can be!_


	9. Chapter 9

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER NINE**

* * *

"How long are you going for?" Lanie asks the next week, standing by Kate's door, holding two coffee cups.

"A couple weeks," Kate responds, tying her sneakers. She grabs her purse and phone, making sure she has her keys before closing the door behind her. "We're leaving next week."

"All right." They stand in silence while Kate presses the button for the elevator. "Okay, so you're in a new relationship-"

"Five weeks."

"Five-week-old relationship," Lanie continues, almost as if Kate hadn't even spoken. She hands Kate's coffee to her. "Oh, here you go. Okay, you need a swimsuit. A hot one. And lingerie, lots of lingerie."

Kate rolls her eyes. "Lanie…"

"You know I'm right, Kate." Lanie gives her a look as the elevator stops at the first floor. "I've seen your underwear drawer. You need some new things."

"I don't think he cares," Kate argues, taking a sip of her coffee. When they reach the sidewalk she throws her arm out to get a cab; normally they'd just walk or drive, but it's the middle of tourism season and Kate doesn't want to deal with parking. It's so much easier just taking a cab. "We've been together over a month, Lanie. Do I really need new lingerie?"

Lanie gives her a look when they slide into a cab. "Really? Of _course_ you need new lingerie. The man is so in love with you it makes me sick, but you have to keep it spicy. Keep him guessing. The last thing you want to do is stop surprising him before the relationship really takes off."

Kate sighs as she leans back in her seat. Lanie's right, of course. She'd just never seen much of a point in spending a lot of money on a scrap of clothing that wasn't going to stay on very long. She had sexy panties, and a couple lacy bras, but for the most part her underwear drawer was full of practical items. Castle didn't seem to mind, but would that little extra something hurt?

"You know I hate shopping," she offers lamely, and she purposely avoids looking at Lanie so she can save herself from the glare she knows she's getting.

"That's why I'm here." There's a finality to Lanie's voice, and aside from some brief planning on which store to go to first, they're silent for the rest of the short ride.

Three hours later Kate's standing in a dressing room, staring in the mirror, scowling at herself. Lanie's convinced her to invest in a few bikinis, and while she loves the idea of Castle's eyes bugging out of his head, she can't keep her eyes off the scar between her breasts, the one on her side.

It doesn't bother her as much now as it did in the beginning; no, it's a part of her, no longer red and angry but beginning to fade into the rest of her skin. But that doesn't mean she wants it to be out there for the whole world to see. Even though Castle has repeated time and time again that it doesn't bother him, that he sees it as a reminder of what they've survived.

"How's it look?" Lanie calls from right outside the door, where she's standing at the ready for size changes or general encouragement.

Kate sighs. It is a nice bikini, a solid red color that's always looked good on her. But it's small. It's so, so small. She pokes her head out and beckons for Lanie. "I'm not coming out in this."

Lanie whistles when she sees Kate. "Damn, girl. Maybe this isn't a good idea, you might give Castle a heart attack."

"Lanie, it doesn't even cover anything." Kate holds the strap of the halter, her arms covering her barely covered breasts, feeling oddly uncomfortable as Lanie studies her. The barely-there scraps of fabric do very little; she may as well just not wear anything and save the money.

Lanie tugs Kate's hands down so she can see the whole thing. "That's kind of the point, Kate. This one's for Castle."

"But I usually wear-"

"Kate, you're hot." Lanie leans against the opposite wall, her arms crossed over her chest. "The man's seen you naked a zillion times, if you're worried about that." She pauses for a moment, and when Kate just looks down at the ground with her palm pressing against her side, she continues. "It's your scars, isn't it?"

Kate just nods, silently cursing the sudden tears that blur her vision. "It's so stupid. Like you said, he's seen me naked. He's seen my scars. Hell, he singles them out, says they remind him of what we've overcome." She motions for Lanie to turn around so she can change. "I just...I want everything to be perfect."

"Come on," Lanie says after Kate tells her she's dressed. "You're getting this suit, and then I'm buying you coffee."

They stumble into a small cafe just a few minutes later, arms full of shopping bags, and Kate saves a table while Lanie orders. Kate leans back and sighs; despite her love of coats and boots, she's never been one for long days spent shopping. She'd much rather save her money and invest in a few solid items than spend hundreds of dollars on things she'll probably only wear a handful of times. But still, they've made smart choices.

And she _is_ looking forward to seeing the look on Castle's face when he sees some of the things she's bought. And letting him peel them off of her.

Lanie plops down across from Kate with Kate's latte and her own tea, and takes a long sip before speaking. "Okay, talk to me. Didn't you tell me that you can see a future with him?"

Kate nods. "Yeah, I can. I want one. I love him, Lanie. I love him so much it scares me sometimes." She sighs after taking a drink. "I mean, we're comfortable around each other. I feel more like myself when I'm with him than any other time, and I think he feels the same way. But I'm scared to death of losing him, too." She groans and leans forward, her head landing in her hands. "God, I'm an idiot."

Lanie reaches across the table to take Kate's hand. "You're not an idiot. Come on, finish your coffee. We're going to find you something you can wear in public, but will still knock his socks off."

* * *

"Hey," Castle greets her the next week, bending to give her a kiss when she opens the door.

"Hi, Castle." Kate smiles, happy but a little frazzled; she overslept, and she's only just finished packing.

Castle shuts the door behind him as Kate retreats back to her bedroom. "You ready to go?" he calls out.

"Almost," she yells back. She pulls her suitcase behind her and she sees Castle eyeing the empty coffee pot when she gets back out to the living room. "Want me to make some more?"

"No, I got us coffee on the way here. It's in the car."

Kate sets her suitcase down and wraps her arms around his waist. "But?"

Castle looks down at her sheepishly. "I kinda drank mine already."

Kate chuckles. "Go ahead and make some. I'm out of vanilla though so I'll pass."

"You should have said something," Castle says casually as he scoops some grounds into the filter. "I would have picked some up for you."

"Castle." Kate takes his hand and tugs, forcing him to turn and look at her after he hits the power button to start it. "Babe, I don't need you to buy me groceries."

"It's just a little-"

"That's not what I mean," she interrupts. She hasn't been so petty that she'd keep a list, but she's definitely noticed that he tends to foot the bill for more than his fair share. He always has, really, since the beginning of their partnership; their date at the Mets game is one of the only things she can ever recall paying for. "You know I can provide for myself, right? Things get tight sometimes, and my suspension will be a little tough towards the end."

"Kate-"

"But I'm fine, Rick." She squeezes his hands. "I know how to budget and I'm pretty damn good at it. I have some savings. I love that you're generous. I love that you want to take care of me. I love that we get dinner and do things together. But I don't ever want to feel like you're footing the bill of this relationship." She sighs and wraps her arms around his back, her chin resting on his sternum so she can look up at him. "Just...can you let me pay for things sometimes?"

After a long few moments of gazing at her, Castle smiles and leans down to brush a kiss at her hairline. "I know you can take care of yourself. You're independent and self-sufficient, and that's one of the things I love most about you." He reaches up to cup her jaw with both hands. "I'll let you buy dinner sometimes."

"And stop buying me groceries."

"That was one time."

"No, you do it all the time, little things like picking up milk on your way here, stuff like that, refusing to let me pay you back." She lets him tug her up into a kiss. When they break, he chases her, but she pulls away before it can continue. "Please let me pay you back when you do that."

"Okay, I can do that." Castle steps away after another kiss and turns back to the coffee maker, grabbing a travel mug from the cabinet and pouring his coffee. He finds the cream, double-checking the date out of habit; it's good, so he splashes some in and swirls the cup around so the cream and coffee blend together. He takes an experimental sip and nods his approval. "Ready?"

Kate smiles. "Ready."

* * *

The drive to the Hamptons is made in relative silence; Castle drives, and typically when he makes it he'll crank the radio and sing along to the music. When Alexis is with him, they'll harmonize, naturally. But Kate told him that she hadn't slept well the night before, and she'd fallen asleep shortly after they'd gotten out of the city.

He doesn't mind; he turns the music just loud enough so he can hear it, and hums or quietly sings along to the songs that he knows. At one point, he has to pull over so he can look at Kate properly. She's facing him, mouth slightly open, with a small line of drool on her chin. He chuckles and wipes the saliva off with his sleeve, then manages to sneak a picture before pulling back onto the road. She'll probably be annoyed when she inevitably finds the picture on his phone, but he doesn't mind; she looks so peaceful when she sleeps, and he wants to be able to look at it any time.

She wakes about twenty minutes before their arrival, and out of the corner of his eye he sees her looking out of the windshield, awe spreading across her features. His house is on the outskirts of town, but they still pass a half dozen or so mansions before they get there.

"I still can't believe you've never been out here," he says, reaching out to rest a hand on her thigh.

Kate takes his hand, curling her fingers around his before sneaking her hand underneath so their palms are kissing. "Well, I still can't believe you've never been up to the Catskills," she teases.

Castle glances over at her with a smile. "Touche." They're silent for the remaining few minutes, their fingers intertwined on her thigh. He slows when he got to his driveway, the garage door opener on his visor seamlessly opening the gate. He wishes he could see the look on Kate's face when she takes it in; the house had been in foreclosure, so he'd gotten a good deal on it, and had gutted and remodeled the whole thing. So while it hadn't cost him the millions of dollars residents usually paid for houses here, it definitely looked like it.

"Castle…" Kate breathes, her nose practically pressed to the window as she sees the front of the house. The car rolls to a stop and she sits there completely frozen while Castle gets out and goes to open her door. She tears her eyes off the mansion to see him with a grin on his face. "I knew you were rich, but this…"

Castle leans forward to brush a kiss against her cheek. "Come on, I'll give you a tour before I bring in our stuff." He unlocks the door with one hand, his other around Kate's waist almost possessively, as if he's afraid she'll run away if he lets go. He winces when they're hit by a wave of musty air as soon as he opens the door. "Sorry," he apologizes, leaving the door open as they step inside. "We usually come up for Memorial Day, throw a big party. But obviously that didn't happen this year, so nobody's actually been here since last fall."

When Kate squeezes his hands in reassurance, he continues,

"So to the left we have the kitchen, dining, and living rooms, that lead to my office and the master suite on that side," he explains, sweeping his arm to the left. "And to the right," he continues, his arm pointing the other way, "are the guest rooms and bathrooms and such. Outside there's a pool, hot tub, I even have a tennis court if we feel so inclined."

Kate raises an eyebrow and tugs on Castle's arm to pull him back to her side. "A tennis court?" she parrots, pinching his side.

"Ow!" Castle gasps dramatically in mock pain, drawing a giggle. "Yes, a tennis court. I'll have you know that I've learned how to swallow my pride on that court."

Kate chuckles, then slides her hand lower, into the back pocket of his jeans, where she palms his ass. "You said something about a master suite?" she says, lifting herself to her toes so she husks her question directly in his ear. "I'd love to see that."

Caste gulps. He kicks the door shut, ignoring the need to open the windows and doors to air the house out right that moment. While his neighbors aren't exactly close, they definitely don't need to hear the noises he's sure they'll pull out of each other in the immediate future. He tugs Kate in front of him and leans down to capture her lips in a kiss that he immediately deepens.

By the time they part for air she's pressed between him and the door, his leg between her thighs and their clothes halfway off. Castle finally manages to tear his lips from her neck when her hips start to roll faster, harder. "Didn't you want to see the master?" he gasps even as she rakes her nails across his lower back. "Fuck, Kate."

Kate fumbles for his belt even as he starts walking them towards his - their - room. "Yes, that's the goal." She pauses her assault on his pants long enough to let him pull the sheets down, but as soon as he turns back around she's on him again, pushing him to the mattress and climbing on top of him.

"Welcome to the Hamptons," Castle gets out before her mouth cuts off his words.

* * *

 _A/N: As always, many thanks to Callie for the beta, all mistakes are mine. Thank you for reading!_


	10. Chapter 10

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER TEN**

* * *

"This is perfect."

Castle looks up from his coffee to see Kate with her head back, face upturned to the sun. Her eyes are closed and lips upturned in a smile. "The coffee?"

She lifts her head to give him a lazy smile. "The coffee, the weather. The company." She smirks over her mug. "Et cetera."

"You're not sick of me yet?" he teases. They've only been here two days, but they've spent every waking moment together, not to mention non-waking moments. They simply can't get enough of each other.

She scoots forward in her chair and finds his calf with her toes. "Not even close."

He gasps when her foot trails up his leg, but before it can get to its presumed destination, he stands. "Come here," he growls pulling her up from her chair and drawing her into a passionate kiss. His hands drift along her hips to cup her ass and he nudges her leg to curl around his thigh.

"Inside?" she gasps when his lips trail across her cheek, down her jaw, to nip at her neck below her ear.

He shakes his head against her. They're on his back deck, but it's far enough from the beach that it's hard for anyone to see them. "Nobody can see us here," he husks into her ear. "We just need to be quiet."

She groans when he lifts her on top of the patio table. "Fuck...that might be hard." Her hands join his at the button of his shorts. "Speaking of hard…"

He silences her with his fingers.

"I wish…" Kate pants a few minutes later, her hand cupping the back of his head.

Castle lifts his head from her chest and props himself on his elbow above her. "You wish what?" he prods when she trails off. When she just shakes her head, he brushes his hand along her waist, over her scar. "Kate? What do you wish?"

She shakes her head again, eyes focused over his shoulder. "I wish I'd said something sooner," she mumbled.

Castle furrows his brow. "Huh?"

"Two years ago," she confesses with a sigh. "When you invited me before."

"But you were with Demming," he argues, taking a step back. He fastens his shorts, Kate doing the same. "You two were going to go away for the weekend."

Kate sighs as she slides back into her chair and runs her fingers through her hair. "No, we weren't." When Castle just stares at her, she continues. "I broke up with him the day you left."

"Shit," Castle breathes, dropping his weight to the table. "I thought…shit, Kate. I thought you broke up later."

"Nope."

"So you…"

"I was going to say yes." Her hand comes out to stroke his knee. "I was going to come with you, but I was too late."

Castle's hand drops to cover hers, his thumb brushing over the back of her hand. "Because I got back with Gina." He squeezes her hand. "I'm so sorry, Kate."

"No," she interrupts before he can continue. "No, Rick, you have nothing to apologize for. You didn't know, and I didn't say anything. But I wanted to tell you. Hell, I'm glad we waited."

Castle looks up in surprise. "You're glad? Kate, we could have been together two years already."

"Technically, yeah. But as much as I like to think I was ready then, to be in a relationship with you, I wasn't." She flips her hand, lacing her fingers through his. "I was still haunted by my mom's case. It didn't consume me, but the slightest nudge could have sent me down the rabbit hole. Roy still would have died, I still would have gotten shot…"

"You don't know that."

"I really think I would have. I love you, Rick. But I would have eventually ran. I would have broken your heart."

They're silent for a few moments before Castle speaks again. "What happened last summer?" he asks quietly, both curious and dreading the answer. The nearly three months after she was shot were hell for him, and he can't imagine what it was like for her. He knows she'd spent it primarily at her dad's cabin, and he'd finished _Frozen Heat_ , but they'd never talked about it, not even since getting together.

"I just needed time," Kate says quietly. "I know how it sounds, but it's true. When you visited me in the hospital...every time I closed my eyes I saw Roy lying on that hanger floor, or you hovering above me in the cemetery." She takes a deep breath and closes her eyes. "I had a hard time differentiating the two, and you were in both of those memories. I just…"

Castle squeezes her hand in encouragement when she trails off.

After a few moments, she nods and opens her eyes. "I think a part of me blamed you for Roy's death. I know it's not logical, but I wasn't thinking logically. All I knew was that Roy had died trying to protect me, and if you hadn't dragged me out of that hanger, he might have still been alive. I might not have been shot."

"Kate…"

"I almost called you dozens of times. Almost every day. But I had panic attacks, almost daily. And I knew if I called you, you'd insist on coming up to the cabin, and I didn't want you to see me like that. Broken." She wipes her cheeks from the tears that had started to fall. "I wanted to be whole. Well, more whole."

Castle stands and tugs on her hand, pulling her up in front of him, and pulls her into his chest. "Jesus, Kate," he breathes into her hair, his cheek resting on top of her head. "I was so mad at you. I'm so sorry."

"I'm sorry too." She leans back so she can look up at him. "Can you forgive me? For hurting you like that?"

Castle just smiles down at her. "I forgave you a long time ago, Kate."

* * *

 _Shit._

 _Oh, shit. Oh, no. No no no. No._

Kate hadn't even thought about it. It hadn't crossed her mind, not until she'd happened to catch a glimpse of the box under the bathroom sink, that she'd stored there ten days before without a second thought.

Over the past year, she hasn't thought much about it. It took her several months to get back to normal after her shooting, and even then, it was still different. A little weird. But it had been normal for a good six months, regular enough that she could predict it almost down to the day. And she'd been a couple days late a few times, but no more than that.

According to her mental calendar, she's at least a week late now.

She stands at the bedroom door, hip propped against the frame, watching Castle. She's accused him of being creepy when he does it, but she needs this moment, needs to reassure herself of what could be, before she climbs back next to him.

He's on his back, one arm flung above his head and the other across his stomach, his chest rising and falling with every breath. She'd been curled up at his side when she'd woken, jerking awake from a dream with a little boy and little girl, both with her hair and Castle's striking blue eyes. At first she'd been confused, but now, that dream makes sense.

She'd been thinking about it a lot lately, what her future with Castle would look like. And she knows it would be wonderful, full of romance and joy and maybe a child or two, and the thought of being with him for the rest of her life excites her. But it also scares her, because she's never felt this way, this all-consuming love that can take over her entire being. She wants a future, wants forever, but is she really ready?

Does she have a choice?

* * *

Castle wakes with the sun in his eyes and his girlfriend on her side, facing away from him. A glance at the clock tells him it's early, and it's rare that he wakes before her, so he presses a kiss to her bare shoulder before sliding out of bed. He'll make her coffee, wake her with breakfast.

He frowns when he notices her when he comes back in from starting the coffee. She doesn't look relaxed, like she usually does when she's asleep. Her eyebrows are furrowed, and he can see her lids fluttering even from several feet away. He's been watching her long enough to know when something's bothering her.

He hears the coffee finish and decides to detour back to the kitchen before waking her; he'll wake her with a cup, with a smile and a kiss. That should start her day off right.

"Kate," he whispers a few minutes later, kneeling in front of her, setting her coffee on the nightstand and tucking her hair behind her ear so he can cup her jaw. The corners of his lips lift when her eyes flutter open, and after a moment, find his. "Good morning."

Kate's eyes flick to the coffee mug and he sees them darken, her eyebrow with a barely noticeable quirk. "Morning." She takes a sip of the coffee, but she frowns and sets it aside.

"Not good?"

"No, it's fine, it's good." She sits up straight and stretches, and his eyes are drawn to the sliver of skin exposed when her shirt rides up. "You hungry? I could use some breakfast."

Castle smiles. "Sure." He stands and holds out his hand, his fingers circling her palm when she takes it. When he opens the refrigerator, though, he turned and gives her a sheepish look. "We forgot to go to the store yesterday," he admits, stepping side to motion to the barren fridge. They have a few leftovers from the last couple nights, and of course cream for the coffee, but very little else.

Kate lets out a low chuckle, but her smile doesn't reach her eyes. "We can go this morning."

"You stay, relax. I'll go."

"No," Kate argues, sliding off the bar stool. "I'll come with you, I just need to shower."

Castle catches her before she can get too far and pulls her back into his chest, his arms wrapping tight around her middle. "Want some company?" he husks in her ear, but instead of a shiver and wiggle of her hips like usual, she squirms out of his arms.

"No, I'll be faster alone."

Castle stands still for a few minutes, dumbfounded. She hasn't had _that_ reaction before, not here in the Hamptons, not even since they'd gotten together. Even if she does shower alone she'll always throw an innuendo back at him, or accompany it with a kiss, or a pinch of his ass. Even if she's annoyed for some reason, he can usually figure out why. He follows when he hears the shower turn on; whatever's on her mind today, she obviously needs her space, so he'll give it to her.

By the time he's back in the bedroom, though, he's changed his mind. They've both gotten better at discussing their feelings. When she's upset, or contemplative, she tends to withdraw, but she'll usually tell him that she just needs to be alone for a little while. Rarely does she just give him the cold shoulder. But today she is. So when she's still in the shower after he brushes his teeth, he strips and steps inside.

"What are you doing?" Kate snaps, the surprise evident on her face.

"Something's bugging you," he returns, turning so the spray hits his back, shielding her. "What's wrong?"

Kate tries to reach around him towards the soap, but when he moves to block her, she crosses her arms over her chest. "Nothing. I told you, I'm fine."

Castle can see the flash in her eyes when she refuses to meet his, the telltale sign that she's lying, which makes him even more upset. "No you're not," he pushes, taking a step forward, crowding her against the tile. "What's wrong?"

"I'm just tired, okay? I didn't sleep well."

He waits a beat before responding, waiting to see if she'll elaborate. But when she doesn't, he shrugs. "All right, fine." He presses a kiss to her forehead before stepping out of the shower. "I'll be back in an hour or so. Do you need anything?"

She answers after a slight hesitation. "No."

"Okay."

* * *

He's just putting the groceries in the car when his phone pings with a text. He can't help the smile that comes at Kate's _I'm sorry about earlier, I love you_ and the accompanying variety of heart emoticons. He fires back an _I love you too_ , then after a second thought, goes back into the store for one more thing.

He's back at the house a few minutes later and carries the groceries inside, calling out for Kate as he walks through the door, but he's met with nothing but silence. After putting the groceries away and arranging the flowers he'd gone back for on the kitchen island, he goes to search for his girlfriend.

He finds her upstairs, in the reading nook on the second floor landing. She's curled up in the bay window, a mug in one hand and a book in the other, a comforter wrapped around her middle. He stands at the top of the stairs, silent, just watching as she turns a page with practiced ease. From here he can't tell what she's reading, but after a few minutes he notices her cheeks start to turn pink, and when she draws her bottom lip between her teeth, he realizes that whatever she's reading is steamy.

So he makes his approach, coming up behind her, and when his eyes can read the words on the page he realizes that she's reading one of his. And not just any of his books. She's reading _Heat Wave,_ and she's on page 105.

"Did you miss me that much?" he teases, and she looks up at him with a smile.

She sets the book and her mug on the floor, scooting forward so he can slide in behind her. She settles back against his chest and lets out a contented sigh. "I'm sorry," she whispers, craning her neck to smudge a kiss to his jaw.

He smiles against her hair. "You have nothing to be sorry for," he assures her. "You said you couldn't sleep last night. Something on your mind?"

"Not really. I just needed a little time to myself." Her fingers trail a path up his thigh, and he groans when she wiggles her hips against him. "You know, I was reading my favorite scene," she adds, turning and settling on his lap, her knees on either side of his hips.

"Oh yeah?" His hands land on her hips almost of their own volition, and when they sneak under her shirt, she shivers. "You want to, uh, act it out?"

She gives him a predatory smile before leaning down to capture his lips with hers, her tongue meeting his and her hips rolling. "Not exactly," she murmurs against his mouth when they part. "I want us to write a new one."

* * *

They spend the rest of the day much like the others, making lunch, walking on the beach, they even swim for a couple hours. Well, "swim" isn't entirely accurate, Castle thinks with a smile as he crawls into bed that night. They'd frolicked a little, until the bottoms of the sinful red bikini Kate had worn "accidentally" came off, and he had no choice but to heed the siren call of her body. Both in the pool and out. And then in the hot tub.

But despite their relaxing day, despite getting lost in each other's bodies time and time again, Kate had still been quiet, withdrawn. So he'd taken care of dinner, the hope that she'd eventually open up to him not quite overcoming the seeds of doubt in his mind. He should ask her, he should push, but when he'd tried that this morning, she'd just shut down again. So he'll wait.

As always, he'll wait for her.

He sets his book down when she slides in next to him, leaning over to give her a kiss on the cheek. "You want to set an alarm for tomorrow? Or just get up whenever?" he asks, lacing his fingers through hers.

Kate drops her head to his shoulder with a sigh. "I don't know, Rick. Whatever you want."

"I just want to spend time with you." He shifts so he's facing her. "Montauk has some pre-Fourth of July stuff, like a mini-festival, and fireworks. Wanna go check it out? Then on the Fourth we can go into East Hamptons, they have a parade and fireworks. What do you think?"

"That'll be fine." She gives his hand a squeeze, then lies down, adjusting her pillow under her head.

"Kate-"

"It sounds like fun, Castle," she interrupts, flashing him a look that he can't quite interpret.

Castle just watches as she turns from him, turns off the lamp on her nightstand, and falls silent. He just stares at her for a few moments before lying down himself. _Tomorrow, then._

He wakes during the night shivering, and, reaching blindly behind him, finds the edge of the comforter and tugs it back over himself. He's almost fallen back asleep when it's pulled off of him again, and he groans, turns over, and sees Kate glaring at him.

"What?" he husks, raising up on an elbow to attempt to keep himself from falling back asleep.

Kate mirrors his pose. "You stole the blankets."

"Huh? _You_ stole the blankets. I woke up shivering."

"No, I stole them _back._ " She tugs the comforter back to herself, but when Castle grabs it back, she huffs and swings her legs over the side of the bed. "Whatever. Have the damn bed to yourself."

Castle sits up on his knees and rubs his hands over his face. "Where are you going?" he asks when he notices her at the door, her phone in her hand.

"To a guest room." She stops, a hand propped on her hips, and looks back at him. "You hog the blankets almost every night."

"Why didn't you say anything before?" he asks after a few moments, her words shocking him into silence.

Kate shrugs. "I just dealt with it. But I'm over it, Castle."

"Over it how?" He hopes she's just talking about tonight, but something in her tone...it makes him wonder. "Kate?"

"Not tonight."

When she turns again to leave, he snaps. "When, then? When will you figure out how to fucking talk?" he calls after her, and he sees her freeze, sees the square of her shoulders.

"That's not fair," she returns, turning to look back at him again. "One night, Rick."

"One night, huh? Are you sure?"

She narrows her eyes, stepping back into the bedroom. "What the hell is that supposed to mean?"

He stands, his arms crossed, facing her from across the room. "It means you're doing what you're best at," he spits out, the anger flowing through his bloodstream, his very skin. "Running away."

The phone flies past his head before he even realizes that she'd thrown it, and he can see her jaw clench before she spits out a "Screw you" and walks out.

* * *

She doesn't sleep. Alone in one of the many guest rooms, she's cold, lonely, and more than a little scared. He'd been mad, and she'd walked away. Over such a stupid thing. Hogging blankets. Really?

She eventually dozes off just before sunrise, when the grey pre-dawn light is just starting to peek over the horizon. She's woken suddenly by a noise, and when her eyes focus to the figure sitting by her bed, she can't stop the laughter from bubbling through her lips. "Ca-Castle?" she finally gets out, lying on her side, facing him. "Why are you wearing a helmet?"

Castle slips off the football helmet with a chuckle and sets it on the floor. "It was just a precaution, in case you were still in a throwing mood," he explains, caution lacing his words. "And maybe to make you laugh?"

Kate sits up and holds out her hand in invitation, which he accepts after just a moment's hesitation. She scoots over to give him room to slide in next to her, and she guides his arm around her shoulders. "I'm sorry, Rick," she murmurs into his neck when she melts into his side. "I shouldn't have thrown my phone at you. I shouldn't have made such a big deal over nothing, or walked out, I should have just-"

"Kate." Castle pushes on her shoulders until she's far enough back that she can look at him, and he cups her jaw, forces her gaze to meet his. " _I'm_ sorry. For the blankets, for suggesting you were running away. It wasn't fair, I had no right."

"You were right though, yesterday. About there being something on my mind. I just didn't…I wasn't sure how to tell you," she admits, feeling her face flush. She reaches up to cover one of his hands with hers.

Castle studies her with his blue eyes and intense gaze, and she tries not to let herself get lost in them. "What's going on, Kate?"

Kate squeezes his hand. "I think…I might be pregnant."

* * *

 _A/N: Thanks to Callie for the beta, and Cathey for listening while I complained about my stupidity and lack of outline for this chapter. The bit with the football helmet is pretty much lifted from "Stay Stay Stay," the song that semi-inspired this whole thing. As always, feedback is always_ _appreciated!_


	11. Chapter 11

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER ELEVEN**

* * *

Castle's mouth falls open. "Pregnant?"

"Maybe." Kate squeezes his hand before letting hers drop. "I don't know. I obviously haven't been able to take a test, but I realized that I'm...well…" She drops her head, suddenly embarrassed. They'd never talked about things like _that,_ so she isn't quite sure how to approach it. "Well, I'm late."

"Ah, that makes sense." Castle squeezes her knee. "I've been your partner for four years. You don't think I've noticed certain patterns in your behavior by now?"

His tone is teasing, but when she looks back up at him she sees the crease between his eyebrows, the concern laced across his features. She lifts her hand to cup his ear, her thumb caressing the dark circle beneath his eye. "I kind of freaked out a little," she whispers in apology.

Castle chuckles. "A little?" He leans forward and gives her a quick kiss. "I have a teenage daughter, Kate. I can handle mood swings and hormones, but I think I'd prefer you just tell me when something's wrong instead of throwing your phone at me."

"Shit, I did do that, didn't I? I'm sorry." Kate sighs, her hand landing on his thigh, her thumb rubbing lazy circles on his skin. "What if...what if I am? I've never really thought seriously about having kids. And we haven't been dating all that long...I mean if I am, then it happened pretty much right when we got together, and…"

Castle places his hand on top of hers. "Kate." He waits until she looks up at him. "We'd figure it out. I'll go get a few tests, okay? Then we can know."

Kate gives him a tight-lipped smile. He sounds confident, but she can see the concern in his eyes. He's worried, too. "Okay. Want me to come?"

"No, you stay. I'll be quick." He climbs out of bed, but before he crosses the threshold he turns and takes the few long strides back to the edge of the bed. He grabs Kate's shoulders and meets her mouth for a kiss, sweeping his tongue against hers.

Kate moans, her arms looping around his neck to keep him close, and she rises up on her knees, presses her front flush against his. They eventually slow, and after a few soft kisses, she hears him sigh, and closes her eyes when his forehead drops against hers.

"I love you," Castle whispers against her cheek.

Kate hums in contentment. "Hmm, I love you too." She bumps his nose with hers, then leans back so she can look at him. "If you hurry I might let you shower with me."

* * *

Castle's phone pings just before he pulls into a parking spot at the store, the same market he'd been to the previous day. He almost doesn't look at his phone, figuring it's just Kate with another "I love you," or something suggestive about the shower. But he does glance at it as he steps out of the car, and the words on the screen cause him to hesitate.

 _We don't need the test anymore._

Oh. _Okay. Do you need anything else?_ He runs inside after receiving her answer, swings through the feminine hygiene aisle, and picks out her favorite ice cream.

When he gets back to the house he finds Kate outside, on the porch off the master suite, curled on her side. "Kate?" he says quietly, setting the bottle of Midol he'd purchased down on the table. He kneels next to her, rests his head on the chair, his face inches from hers, and smiles as her eyes flutter open with his fingers at her hair. "Hey. You all right?"

Kate winces when she sits up. "Just cramps. I couldn't find anything in your bathroom, and I didn't want to snoop too much upstairs."

"You can snoop all you want, Kate." Castle hands her the water and Midol, and after she swallows some down, settles on the chair beside her. "You're not a guest here," he reassures, one hand cupping her cheek and the other resting on her waist. "You're part of the family."

Kate scoots closer, allowing him to lay them down, their noses almost touching. "I'd hate for Alexis to think I was going through her stuff." She bumps her forehead against his. "Thanks for getting me drugs," she teases.

Castle leans forward and pecks the tip of her nose. "Always." He gazes at her for a few moments, his arm supporting his head. "Can I do anything?" he adds when he sees her wince and squirm her hips a little. He's watched Alexis go through cramps enough times that he knows he's pretty much helpless, but he presses the back of his hand low on her abdomen anyway, hoping some pressure will help.

Kate's eyes flutter closed and she lets out a low groan. "That's helping already. Thanks, babe." They lie in silence for a few minutes, Castle's knuckles kneading, the occasional sigh escaping through her lips. Eventually, she breaks the silence. "I'm so sorry, Rick."

"For what?"

"For not telling you right away. I just…" She sighs. "I didn't know how you'd react. We _just_ started dating. It's not even in the realm of the conversation yet: kids, hell, even our future. We're still finding our footing, and all of a sudden I might be _pregnant?_ "

"Kate…"

"I mean, do you want more kids?" She opens her eyes when he stills, and he's just staring at her with wide eyes. "I shouldn't have asked…"

"No, no," he reassures her, his hand curling around her waist. "I want nothing more than to have a family with you, Kate." His fingers work at the base of her spine, eliciting a low groan. "And I don't see us as having a new relationship. Yeah, we've been romantic for less than two months. But I've been your partner, and loved you, for much, much longer."

Kate's cheeks flush, and she hums. "I have too," she admits in a whisper. "I think…no, it's stupid."

"What?" Castle pushes, his voice soft, hand squeezing her hip in encouragement.

"I just…" She trails off, gazes past his shoulder, at the wide yard and the beach beyond. "You know about my relationship with Will." At his nod, she continues. "I'll admit, we never would have lasted. When we dated, I wasn't in a great place with my mom's case. I wasn't drowning in it like I had before, but I couldn't let it go either. I'd spend most of my days off going through the file, and to be honest, I hid most of it from him. He knew about my mom, of course, knew how much I had struggled. How much your books helped me." She nudges his knee when he grins. "Shut up. Anyway, we were pretty serious. So when he left, didn't even consider giving it a chance…"

"It hurt," Castle interjects. They'd had part of this conversation before, in one of their many dinners at Remy's, but it's so rare that she opens up to him that he doesn't pry any more than that.

"I was devastated," she agrees. Her fingers play with the sleeve of his t-shirt, sneak underneath to brush along his skin. "But I got over it, over him. And I swore to myself that I wouldn't go through that again, I wouldn't love like that again...and then you bulldozed your way into my heart."

Castle lips widen into a grin, and he surges forward to kiss her, nudging them until he's hovering over her. He trails his lips down the long column of her neck, nipping at her collarbone, his tongue darting out to taste the dip at the base of her throat. He pulls back when her hips start to cant up into his; they can't, not now, but he wants to. God, he wants to.

"Kate," he breathes, lifting his head to gaze into her eyes. She's staring at him with wide eyes, open and honest, and full of something he can only describe as overwhelming love. Like she's already thinking of forever.

"Castle," she gasps, carding her fingers through his hair, "I want this. A family. Forever." She chases him, her lips brushing against his. "But not yet. I want to enjoy _us_ first. For a little while, anyway. Let's revisit this conversation later. Say, six months?"

Castle props himself on his elbows, his hips in the welcoming cradle of her thighs. "Six months, huh?" He considers her for a moment before giving her a smile. "It's a date."

* * *

He's never seen her like this.

Well, he has, to a point. This summer she's been more relaxed than he's ever seen her, more vibrant, more outgoing. She's always been good around people, when not arresting them, of course. But right now, he's seeing a different Kate.

They'd decided to have lunch in a pub after the 4th of July parade. Most people are a little tipsy, both from alcohol and the general happiness of the day, and his girlfriend is definitely in that category.

He's nursing his beer as he watches her play pool, absolutely annihilating the two college-age guys who were dumb enough to challenge her to a match. They'd even turned it into a tequila contest, and while her opponents are quickly approaching drunk, Kate only seems buzzed. He tips his drink in a salute when she throws him a grin, and when she sinks the 8 ball to win a third game, her cheer is contagious.

"One more?" one of the guys asks, loudly, and Kate laughs and just shakes her head.

"I don't think your pride can take the hit," she teases, hanging her cue on the rack. She sidesteps when the guy reaches for her, instead heading towards Castle. "I'm done, guys. Thanks for the drinks."

Castle's only slightly taken aback when she goes back to him and pulls him in for a kiss. His tongue welcomes hers, and he drops his hands to lightly squeeze her hips. The guys had been flirting with her the entirety of their games, despite her being very clear about her relationship status. He grins at her when she pulls away. "Shouldn't I be the one marking _my_ territory?"

Kate blushes. "Shut up, okay? They were starting to piss me off. Can we get out of here?"

"Of course." He throws enough on the table to cover their meals, plus a generous tip, while she stops at the restroom. "What do you want to do for the rest of the day?" he asks when she's back, leading her outside. "We have a few hours until we should stake out our spot."

Kate wraps her arm around his waist, leaning into his side when he drapes his arm around her shoulders. "I don't care," she confesses, her head against his bicep. "I just wanna spend it with you."

Castle chuckles when she almost trips. "You're tipsy."

"No I'm not," she argues, nudging his shoulder. She giggles. "That was fun."

"What, the parade? Or kicking the asses of cocky twenty-somethings?"

"Definitely the ass-kicking." She pulls away and grabs his hand, tugs him towards the park where they'll be able to see the fireworks. "Come on, let's find a spot now."

They spend the afternoon under the shade of a tree, lounging on the blanket that he'd brought. He's glad he'd had the foresight to suggest they bring books, although hers goes mostly unread when she dozes next to him. He watches as the park fills with people; some lay out blankets like him, some just stand around.

Kate wakes shortly after the sun starts to set, and she glances around, brows furrowed. "How long was I out?"

Castle smiles, his hand providing support as she pulls herself back into a sitting position. "A couple hours. Sleep off your drinks?" he teases, his thumb rubbing over her knuckles.

She shoots him a smile. "Oh please. Hand me my purse? I'll be right back." She returns in just a few minutes, and settles back on the blanket. "I'm glad I'm here with you," she mutters into his ear, her nose nuzzled against his neck.

Castle turns his head to capture her lips with his. He cups her jaw, thumb brushing the shell of her ear. "Me too," he whispers against her mouth. Her smile is contagious, but their moment is interrupted with the first flashes of the fireworks. Rick can't concentrate on the fireworks in the sky, however; his gaze keeps wandering to his girlfriend, eyes wide with wonder. After a few minutes they stand to see them better; Kate settles in front of him, and he wraps his arms around her waist and pulls her close.

Kate's arms land over his, and her fingers trickle along his forearms, and she giggles when Castle nips at the sensitive spot behind her ear. She wiggles her hips against him, eliciting a low groan. "These fireworks are amazing," she says, her head back so only he can hear.

" _You're_ amazing," he returns, smudging a kiss at her temple. They're silent as they watch the show, save for the occasional gasp or exclamation when an extra impressive firework bursts above them. Castle keeps his arms tight around Kate, who's tucked under his chin, eyes glued to the sky.

They're going home the next day, back to the city and their apartments and their lives. He's enjoyed their time here more than he ever thought he would; they've always had great chemistry, but their transition from friends to lovers has been almost effortless. Despite the great time he's had, though, he's happy to go back to the city, to go home. Where they fell in love.

By the time the fireworks have ended and most of the spectators have left, save for some partiers, Castle drops his chin to Kate's shoulder. "Ready to go?"

Kate turns her head, her nose nudging his cheek, and she grins against his jaw. "Yeah, I am."

* * *

 _A/N: As always, thank you for your support, and Callie for the beta! Any mistakes are mine. Feedback welcome!_


	12. Chapter 12

**IT'S BEST IF WE BOTH STAY  
** **CHAPTER TWELVE**

* * *

"You're sure you don't want to come back to the loft?" Castle asks the next afternoon as Kate unlocks her door.

She shakes her head even as she steps inside, and she turns back to him, reaches for his hand. "I'm sure. You need time with your family."

Castle follows her inside, her suitcase in tow. "But you're part of my family, Kate."

Kate pauses, her hand on the door. "Castle," she whispers, before she turns to him and loops her arms around his neck. "You can't say stuff like that when I'm trying to say goodbye."

Castle grins, his fingers twining at the small of her back. "Well, maybe we shouldn't say goodbye yet." He pulls her into him, taking a step backwards so his back is against the door.

She steps between his legs, her fingers playing with the soft hairs at his nape. His hair's grown over the weeks they've been together, and he hasn't shaved in several days, either. It's definitely a look she can get used to. She cups his jaw and runs her fingers along his beard. "Maybe you're right." She lifts on her toes so she can reach his mouth, and he responds immediately, his arms tightening around her.

One of them moans, she isn't sure who, but before she knows it he has her pinned against the door, a leg between hers. She rolls her hips, their lips parting on a groan, and she drop her head to his shoulder when she remembers they really shouldn't right now. Rick has to pick Alexis and Martha up from the airport in just a few hours, and he needs to stop at home first. He'd had his housekeeper go by when they were gone, but he'd wanted to unpack before heading to the airport.

"We can't," she groans, and she feels his chuckle reverberate through them both. "You don't have time."

Castle pushes her back a few inches. "I hate it when you're right," he teases with a wink.

Kate rolls her eyes, but she can't stop her smile. "You love it when I'm right," she returns. "Why don't the three of you come over for dinner this weekend? I'll make that spaghetti you liked."

"Only if you let me bring the wine from that night." Castle squeezes her hips.

Kate draws her bottom lip between her teeth. "I did like that wine," she admits in a low voice, listing into him again.

"And I liked what came after that wine. I ordered two cases of that wine. They're due to arrive tomorrow." He leans down to kiss her again, but before she can deepen it he pushes himself off the door. "You are right though. I need to go."

Kate leans against the door when she opens it, what she's sure is a goofy smile on her face. She can't help it; despite the occasional squabble, and of course the pregnancy scare—he's already jokingly promised to hold the phone throwing incident against her at some point—the trip had been great. She can't remember the last time she's felt this relaxed, this happy. And she knows why: him. Castle makes her happier than she's ever been.

Castle turns after he crosses the threshold, and gives her a concerned look. "You okay?"

"Yeah," she says, her arms sliding around his waist, head tucking under his chin. "I had a great time, Rick. I miss it already."

"We can go back at any time." He wraps his arms around her. "Just say the word and we're gone."

Kate smiles against his shirt. "Tempted to say it now," she admits, squeezing her arms before letting go and stepping back. "Say hi to Martha and Alexis for me?"

Castle smiles and cups her jaw, tilting her head so he can give her a soft kiss. "Will do. I love you."

"I love you too."

* * *

"Dad!"

Castle grins when Alexis launches herself into his arms, her carry on dropped at his feet. He squeezes her tight, letting go after a few moments and reaching for his mother next. "Welcome home. How was your flight?"

"Marvelous, darling," Martha chimes in, pressing a kiss to his cheek. "Your daughter spent most of it rewriting her journal, color-coding and making sure there's enough room for ticket stubs and the such."

Castle chuckles. That sounds like his daughter, all right. He keeps his arm around his mother's shoulders as Alexis takes a detour towards the restroom. "Well, I can't wait to hear about it. You two must be exhausted though."

Martha pats his waist. "That we are." She lets go when he steps forward to get one suitcase, but when he's back by her side, she continues. "How's Katherine?"

"Good." He's sure the grin on his face is ridiculous, but the mention of Kate's name fills him with joy like nothing else does. "She's good." He sees the other two suitcases and grabs them, loads them onto the cart he'd rented from the airport. Alexis appears back at his side, and he puts his arm around her shoulders and drops a kiss to the top of her head. "Ready to get home?"

"Please," Alexis begs with a yawn as she leans into his side.

Rick leads them to the car, settling in the middle seat as the driver takes care of the bags. He was about to ask them to start telling him about their trip, but by the time the exit the parking garage, both ladies are asleep beside him. He smiles to himself and pulls out his phone, brings up Kate's contact. His fingers swipe across the screen as he sends her a message.

 _What are you up to?_

He chuckles when her text comes in within moments; he likes to imagine that she was staring at her phone, waiting, but most likely she happened to have it near her.

 _Just finished a bath._

He stifles a groan; oh, to be with her in that bath. _Any pictures?_ He can almost see the way she's probably biting her lip at his response, maybe curling a strand of hair around her finger.

 _Maybe next time. Martha and Alexis get in okay?_

 _Yeah, right on time. They're both passed out. Wanna come over? Have a sleepover?_

 _Castle._ She's probably rolling her eyes. _I'm going to bed, I'm meeting Lanie for breakfast. Talk to you tomorrow._

 _Well, damn. Sleep well, I love you._

 _Love you too._

He closes the message and opens Angry Birds, spends the rest of the ride home trying to beat his own high scores. They've only been apart for a few hours, but he misses Kate. Misses her hand in his, the way her head nestles under his chin when she's not wearing heels. How she tucks her hands in the back pockets of his jeans to pull his hips into hers.

They'd agreed to shelve any talk of their long-term future for several months, but he's already planning, already thinking of looking for a ring.

No point in delaying the inevitable.

* * *

"Katherine, darling, welcome."

Kate grins as she's swept into Martha's arms a few days later, the older woman spinning her around with a hug. "Hi Martha," she giggles, tucking a stray hair behind her ear when they part. "It's good to see you."

"You too, darling." Martha releases her and led her into the kitchen. "Wine?"

"Please." She sets her glass down after a few sips, and glances around the empty living room. "No Rick or Alexis?"

Martha gives her a knowing look. "They ran out to the store. But I have to tell you, I haven't seen him this happy in a long time."

Kate feels her face flush, but Martha continues before she can respond.

"The way my son's face lights up when anyone says your name, or when you call or text him; I haven't seen him look like that for anyone."

"Well, I-"

Martha interrupts with a hand on her arm. "No one, Kate. No one has put a smile on his face like you have."

Kate can only smile. "I feel the same way about him." She turns when the front door opens, and she sees the object of their conversation and his daughter walk in, grocery bags in each of their arms. "Hey, guys."

Castle freezes mid-word when his eyes meet Kate's, and he grins, his whole face lighting up. "Hey," he says, setting his bag on the counter and tugging her in for a soft kiss. "Sorry, we were out of ice cream."

Kate returns his kiss, mindful of his family in the room and keeping it short and her hands above his ass. "Well, we can't have that," she teases, pinching his side. She pulls away and looks in the bag, glancing back at her boyfriend at the contents, an eyebrow raised. "Ice cream, huh?"

Castle shoves his hands in his pockets. "Well, you can't have ice cream without all the toppings," he admits. He leans in close, his mouth next to her ear. "I got extra whipped cream."

Kate nudges his chest with her shoulder, ignoring the sudden flush at his words. "Shut up. Where's your daughter?"

Kate finds Alexis by the coat closet, slipping off her shoes. "Hey, Alexis, can I talk to you for a second?"

Alexis gives her a wary look before nodding, and if Kate is honest with herself, she can't blame the teenager. Alexis doesn't know everything that Kate has gone through, but she does know that Alexis has witnessed the ups and downs of her father's relationship. And, until right before leaving for Europe, most of the relationship had consisted of downs.

"I know things haven't been great with you and me lately," Kate begins, and when Alexis just raises her eyebrows, she sighs. "Look, I messed up with your dad. I never intended to hurt him, but I felt like I needed to protect myself. And in the process, I did hurt him."

"Do you know what he did last summer?" Alexis interrupts, crossing her arms. "For the three months after you were shot. At first, he spent every waking moment in the precinct, trying to find your shooter. And when Gates kicked him out, he brought all of that shit home. He kept waiting for something to happen, for some lead to show up. He'd stare at the photos and statements and everything until he couldn't keep his eyes open anymore, and then when he did fall asleep, it was rarely in his room."

"Alexis-"

"He passed out on the couch most nights. And almost every night he'd have a nightmare, wake us up with his yelling." Alexis pauses to take a deep breath, then continues. "But you know what was the worst part? The worst part was how he'd carry his phone around, constantly checking it for notifications, even when there weren't any. He just wanted two things last summer: to find your shooter, and for you to call him." She shakes her head. "Why didn't you call?"

Kate sighs, and expects Alexis to continue; obviously she's been holding this in, and the least she can do after hurting Rick, after hurting his family, is to let her get it out. But Alexis remains silent, leaned against the door with her arms crossed, and Kate takes the opportunity to respond. "I had a rough time that summer," she admits on a sigh. "Now isn't the time to explain it all. Hell, when I look back on it, I _still_ kick myself for not picking up the phone. If only I'd called him, maybe I could have saved us from months of dancing around, and from so much heartache."

She reaches out to touch Alexis's arm, and when the teen lowers her arms, Kate takes her hand. "Your father and I have talked a lot about our relationship. About where we've come from, how we could have handled things differently. We've both messed up on things, but that's what relationships are. People screw up, but what matters is whether you take the time and effort to mend anything that's broken. And we've done that. We're still doing that, and we'll continue to. As long as your father will have me, I will try to make up for hurting him."

After a long moment, Alexis lifts her head to meet Kate's eyes. "You love him?"

Kate gives her a small smile. "With every fiber of my being." She's a little surprised when Alexis pulls her into a hug, but she wraps her arms around her, squeezing her tight.

When they part and turn back to the kitchen, Kate tries to ignore the shimmer in Rick's eyes, but when he mouths _thank you,_ she has to swipe at her eyes.

Alexis and Martha are the most important people in Rick's life, besides her. She's always felt welcome in their home, but now? Now, she feels like _family._

* * *

"Kate?"

Kate turns at the voice and smiles at her boyfriend as he pads into the kitchen, clad only in his boxers, hair mussed from sleep. "Good morning." She holds out a mug, which he accepts with a gracious smile. "Sleep well?"

Castle takes a long sip, humming his appreciation before pressing his lips against hers in a soft kiss. "You know how I slept," he teases.

She chuckles into his mouth. Yes, she certainly does; today is her last day before returning to work, and they'd been up most of the night, trying to take advantage of the ability to sleep in without an alarm clock.

It's still early, though; Kate had woken up before dawn and hadn't been able to fall back asleep, despite the warmth of Rick beside her. After lying there for the better part of an hour she'd finally relented, and went for an early morning run. It had helped clear her head of whatever had interrupted her sleep. Now that she's home, though, she realizes that the run wasn't the only thing she needed.

She takes her coffee in one hand and Castle's in her other, and leads him to her office. Letting go of his hand, she rifles through a box beneath her desk and takes out a smaller one, about the size of a photo box.

"What are you doing?" Castle asks when she opens the lid.

Kate tugs him closer, to the window, where she opens the shutters to reveal her makeshift murder board. "I want to take this down," she says, and when Castle just gapes at her, she steals a kiss.

"Kate-"

"It's time, Rick." She gives his hand a shake and prods him to stand next to her. "We hit a dead end. Evelyn can't find the missing picture, so we'll probably never know who's responsible for it all."

"Maybe there's a way," Castle interrupts, his eyes a little wild, the way they get when he gets an idea. "We can ask other guests, track down more negatives-"

"Castle. No." She turns, takes both of his hands, stepping in front of him and waiting until he looks at her. "It's okay, really it is. I don't know if I'll ever get justice for my mom. But, do you know what I've come to realize, especially the last year?"

"What?"

"It's okay. Her case used to be all I had. If I wasn't working, I was buried in her file. But now, I have more. I have _you_." Her lips lift in a smile. "You and your family are the best thing that's happened to me in a long time," she admits. "And Mom wouldn't want me to risk losing you."

Castle bends down, resting his forehead on hers. "There is nothing you could possibly do to lose me, Kate. But if this is something you have to do, I'm right beside you, all the way."

* * *

 _A/N: Thanks Callie for the last-minute beta, any mistakes are mine._

 _A/N 2: This is the final chapter, save for an Epilogue that I plan on posting in the next few weeks. I have so much gratitude to everyone who's come along on this journey. I will always be grateful for your tweets, follows, favorites, reviews, etc. Thank you!_


	13. Chapter 13

**IT'S BEST IF WE BOTH STAY  
EPILOGUE**

* * *

Kate drops her bag with a sigh one night in early December, and she takes a moment to collect her thoughts before stripping off her coat. She gives Castle a smile when he appears at her side with a glass of wine. "Thanks, babe." She takes the drink and his accompanying kiss, grateful for her boyfriend's intuition.

He'd left the precinct after the case had wrapped, but Kate had stayed behind, asked by the federal agent they'd worked with for a minute alone. Castle had retreated to get a head start on dinner and draw her a hot bath.

"Everything okay?" he asks, following her into the kitchen.

Kate pauses, wine glass at her lips, before taking a long sip. "I think so." She reaches for Castle, and when he takes her outstretched hand, she leads him to the bathroom, where he had indeed filled the tub with hot water. After undressing she dips a toe in the water; finding it perfect, she sinks in with a satisfied hum. "You're joining me, right?" she asks, giving Castle a look. Castle strips and settles in behind her, his arms banding around her stomach to hold her to him. "Dinner will be ready soon," he husks in her ear, "but I can't say no to you in the bath."

Kate chuckles and leans back into him, her head at his shoulder. "Thank you for doing this."

"Of course." Castle presses a kiss to her hair, nuzzles her temple. "What did Stack want?" he asks after a long silence.

"Hmm." Kate lets out a grunt, forces her eyes back open. "He, uh, offered me a job."

"What?"

"Yeah. Well, kind of." She leans forward so she can turn to face Rick. "He wants me to apply for an opening with his team."

"In the AG's office?"

"Mm-hmm."

Castle follows her out of the tub and wraps a towel around his waist before handing her one. "Wouldn't it be in DC?"

Kate nods as she knots the towel between her breasts. "Yep." She slips into leggings and one of Castle's sweaters, gripping the ends of the sleeves to stop herself from reaching for him as he puts clothes on. Normally they'd migrate from the tub to bed, but she can hear the oven beeping, and she doesn't want their dinner to burn. As hungry as she is for her boyfriend, she hasn't eaten since the small lunch she'd scarfed down hours before.

When she sees what he pulls out of the oven, she groans. "Oh, Castle, lasagna? I love you."

Castle chuckles as he dishes out servings. "It's like I know you or something," he teases. They settle on the couch and start eating, an unspoken agreement to pause the conversation for the dinner they both desperately need. He finishes first, sets his plate on the coffee table and waits for her to finish. "You're applying for it, right?"

Kate swallows her last bite and shifts to face him, tucks her toes under his thigh. "You think it's worth it? I probably wouldn't even get it."

"Oh, please," Castle scoffs, his hand landing on her shin. "You totally would. But yeah, I think it's worth exploring, for sure."

Kate nods and finishes her glass of wine. "Okay. I'll call first thing in the morning."

* * *

Castle wakes to an empty bed a week later, an indent in the pillow next to him but the sheets cold. A quick glance around Kate's room confirms that it's empty, save for him. He grabs his robe when he slides out of bed; they hadn't turned the heat on when they'd stumbled through the door hours before, too busy grabbing at each other after an evening of teasing at the precinct Christmas party.

A glance at his phone tells him it's only been a few hours since he'd collapsed at her side. He steps into his slippers before padding out of the bedroom; the living room is dark, but he sees a light coming from the spare room, the room that doubles as an office. It used to house a murder board, but since he'd helped take it down five months before, she'd converted the room to more of a guest space.

"Kate?" he calls out when he spots her, sitting on the bed, her head down. He notices her hands in her lap, sees the chain reflect in the light. "Sweetie, are you okay?"

The look in her eyes when she meets his is so sad, so child-like, that he rushes to sit next to her. His hand covers hers, stilling the work of her fingers against her mother's ring.

"I'm sorry," Kate whispers, but he shakes his head, almost cuts her off with his reply.

"No, Kate." He drapes his arm around her shoulders and pulls her into his side, feels her exhale and eventually relax against him. "Why are you apologizing?"

"I thought I was okay." She presses her cheek against his chest, and he has to bend down to hear her muffled words. "Mom died in January, and our Christmas stuff was still up. So, this time of year, it's hard. Everything reminds me of her. And then this DC thing..."

He squeezes her shoulders and presses a kiss to the top of her head. "Oh, Kate…"

"Usually I'm okay, I can push through it. And I have been, but tonight...I had a dream about her. The first one in a long time." She clutches him even tighter. "I miss her, Rick," she admits after a long silence, her voice small. "I wish she was here, I wish I could ask her advice. She'd ask the right questions, lead me to the right decision."

"There is no right decision," Castle counters. "But there's no wrong decision either. It's a great job offer, Kate. Would it be hard? An adjustment? Of course. But we would make it work." He leans back and releases her so he can see her face. "I will support whatever decision you make, you know that, right?"

"I don't want to lose you."

"You won't." Castle rubs his thumb across the back of her hand. "You couldn't even if you tried."

That earns him a smile, and Kate leans back into him, knocks her temple against his shoulder. "I'll never try." She stands after a long moment and lays the necklace back in the box that houses mementos of her mom. "I'm gonna get some water, I'll meet you back in bed."

He follows her to the kitchen, ignoring her suggestion. He's not leaving her side, not now, not ever.

When they'd been at the Hamptons in the summer, they'd agreed to shelve any discussion of their long-term future. They wanted to enjoy their relationship as it happened, enjoy being together without the pressure of fitting inside a label. He knows what he wants, though: he wants to be with Kate for the rest of his life.

They have a little over a month left in their six-month timeline, and he has no idea if she still remembers it, but he has the date marked in his calendar. And whether they're in New York, or whether Kate accepts the offer at the Attorney General's office and they're together in DC, he plans on being with her every step of the way.

* * *

Not for the first time in her week-long tenure as a federal agent, Kate wishes she had never accepted the job. She misses her precinct, her city, her boyfriend. She and Rick had decided that he'd return to New York after helping her move, to let her settle into the new job and apartment.

He's going to be there to visit in a few days, and she can't wait. She's always been proud of her independence; she'd become the youngest female NYPD detective thanks to her own determination, and the tutelage of Roy Montgomery. But here, she doesn't have a mentor. She fits in with her team, but she doesn't know any of them well enough to confide in them her doubts and insecurities. What she needs is Castle's optimism, his encouragement, his warmth at her back at night.

It's hard for him too, she knows. They talk every night, and just last night he'd admitted that he didn't realize he'd miss her so much. But he'd been by her side almost every day for the better part of four years, and while their brief separations aren't quite as painful as those first summers apart, she aches for him now.

Maybe taking the job wasn't the right move. Maybe it's too hard, too much to take on. Maybe Castle should have stayed more than a couple days, helped her adjust more to her new surroundings.

She's so lost in thought as she walks through the door that it takes her several steps to realize that something's different. When she'd left that morning all the lights had been off, but now, one beckons from her bedroom. She glances into the kitchen; there's food on the counter, food she definitely didn't have before. Her mind races with possibilities. The only person who has a key, besides her, is Rick. Dare she hope?

Her hand rests on her gun anyway, muscles tense, ready to draw if whoever's here really is unwelcome. As soon as she sees the familiar back of her boyfriend, though, she relaxes and clears her throat, sets her gun on the dresser.

The surprise on Castle's face morphs into joy when his eyes meet hers, and she laughs when he sweeps her into a hug.

"Hi," she laughs, arms circling around his shoulders, burying her face in his shoulder when he lifts her from the ground. "This is a surprise."

Castle drops a kiss to her neck before setting her back down. "I couldn't wait until Friday," he admits, arms banded around her waist. "You seemed so sad last night, I booked a flight as soon as we got off the phone."

Kate cups his cheeks and tugs his face to hers, surges into him. Their kiss is rough and desperate, tongues insistent, and they paw at each other even as they stumble to the bed.

"God, I missed you," she gasps after Castle collapses at her side, her hand finding his.

Castle lifts their hands to brush a kiss against her knuckles before pushing himself off the bed. "Me too," he agrees. He leans down to kiss her when she tries to pull him back. "I wanted to surprise you with dinner but you were earlier than I thought you'd be."

Kate whimpers at the loss of contact when he pulls his hand from her grasp. "It's almost eight." She stares as he rearranges his clothes; they'd only half-undressed in their need for each other. "Hang on, I'll help."

"No," Castle protests, nudging her back down to the bed. "You get changed into something comfortable, relax. I got this."

She joins him in the kitchen after changing into leggings and a sweatshirt, ignores his insistence that she retreat to the couch with her wine. He'd picked up her favorite wine, and as she sips it, she can already feel her blood hum again, sing with desire. She needs to eat, though, so she cuts vegetables while he puts the meat in the oven.

He pins her against the counter while the food is cooking, and as soon as his hands slip beneath her sweatshirt, she's a goner.

"Good wine choice?" he pants against her cheek after they still, Kate's legs locked around his waist, hanging half off the counter.

Kate chuckles, a low, hoarse sound in her throat. "Good everything choice." She gazes at Rick when he swipes his hand across her forehead, brushing back the hair that's escaped from her ponytail during their two frantic rounds. His face is so soft, so tender, and her heart swells with love for this man who seems to know exactly what she wanted. Who was so willing to drop everything and fly to another city for her.

They haven't talked about it in specific terms, but she assumes that at some point he'll move in with her, after she's settled a bit. But as his fingers dance across her forehead, his own forehead creased with worry, she knows that she doesn't want to wait for that conversation. She'll settle into her new life much easier if he's here too.

"Rick?"

Castle's fingers continue their exploration of her skin. "Yeah?"

She reaches up and covers his hand with hers. "Will you marry me?"

He stills and his eyes meet hers, bright and shocked. "I...are you serious?"

"Yes." Kate pushes him back so she can tug her pants back on and scoot back to sit on the counter. She takes his hand again and holds it to her chest. "I'm serious. Richard Castle, will you marry me?"

"Hang on." He disappears into the bedroom, and Kate can hear some rustling, a quiet "a-ha!" before he reappears. His hand is behind his back, and Kate eyes him, an eyebrow raised, a hunch in her gut but words caught in her throat.

Castle pulls her off the counter so she's standing, and it isn't until he kneels that he brings his hand back in front of him. Between his fingers is a ring, an impressive one based on the way it sparkles in the dim light, and he takes her left hand in his. "I was going to plan something nice," he admits, the worry in his eyes betrayed by the smile on his lips. "But you beat me to it."

Kate's laugh is contagious, and she joins him on the floor, molds her body to his. "So," she gasps between kisses, "is that a yes?"

Castle sits up, bringing her body with his as he stands and walks them to the bedroom. "That's a hell yes."

Neither of them care that dinner burns and they end up ordering take out; they're getting married, and for the next several hours, that's all that matters.

* * *

 _A/N: As always, my eternal gratitude goes out to two parties: to Callie for being with this fic every step of the way, from inception to completion, for providing words and ideas when they failed me. And to you, the fans, for your dedication, for following and favoriting and reviewing. As much as I have fallen in love with this little universe, it makes it a whole hell of a lot easier to write when I know people will actually read. Thank you!  
_


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